I'm going to review the details of the then and now of art ripping, how it's done and how to combat it, before and after it has been stolen.
The purpose of this article is to help people who are frustrated with spotting their own and other's art work places on the web it does not belong. A crucial step in combating this is understanding it, so we'll go through the details!
Art Theft in History
Traditional Art Theft had two forms.. straight up stealing the actual art piece, from private or museum collections and selling them black market, to reproducing them. Reproduction of physical (not digital) art is an art form in and of its own right, and in many ways requires a greater technical knowledge and mastery of art then the very artist being copied may have. Properly duplicating art is a painstaking process involving a multitude of steps, from identifying the actual makeup of the paints used (their chemical breakdowns, sources, etc.) obtaining replicas or originals of the inks and materials (canvas, etc.) utilizing the same brush sizes and makes as the original artist (and other tools) replicating their specific color mixing and ink layering techniques, brush stroke techniques, pressure applications.. you can see where this is going! The masters of art duplication are respected professionals and can reproduce any art piece in existence so perfectly that not even chemical analysis can separate the original from the duplication (they even have methods for accelerated aging, fading and cracking methods.)
Art Theft Now: Digital Thievery
Today, art is stolen digitally. All art forms get lifted (stolen) by computer very easily and for a multitude of reasons. The biggest is ego, people want to be seen as accomplished, creative, and intelligent; the means to reaching this fast is generally by lifting the work of other people who portray artistic sensibilities and stylings that the thief wishes to have. These are the hardest thieves to combat, since they generally do not profit from their thievery in any monetary way, are often underage, and generally just have no motive or common decency that would make them bend to threats (we'll tackle some methods that can be effective against them later.)
As well, websites that sell subscriptions to access "premium" digital art are now cropping up and offering art from 'contributors' who have, well, no clue they're contributing to begin with. These are easier to work against if they speak a language you do too.
Similar to above are sites offering printed artwork that lift the work from other places without paying the actual artist. These can be very hard to deal with as they do not have a need to remove signatures from the art before selling it, since that's part of the art piece anyways!
How It's Done
Well, there's only three things a person needs to steal art; a right mouse button, a print screen key, or a screengrab tool. Between these three, there is absolutely no way to hide art from a thief. Beyond this, there are more advanced methods of pulling art at higher resolutions from Flash files and websites, attempts to use CSS code to "hide" the image from the right mouse key's context menu.. etc. Basically, I can personally get any image off a file or webpage put on my screen, and if I can do it, any art thief can do it, and probably faster.
The Useless Fight
There is no way to stop someone from being able to get a file off a webpage and on to their hard drive (technically they do it the moment they load the page, at the very least, it enters their RAM.) Ask the professionals who've been trying to combat this for ages.. Flickr, Google/YouTube, Break.com, etcetera.. there's just no stopping a determined kid and his computer.
Basically, don't expect DeviantART or any other website that might host your art to do much outside their legal obligations to protect your art from theft. (their legal obligation is to notify of copyright status, that's all.) Your art is your own problem, and if you care about it, you'll combat ripping yourself, or learn to deal with it. (I just deal with it, personally.)
Stopping Thieves before they Steal
Despite the above, there are a few ways to discourage a ripper. They are sometimes effective, and sometimes they aren't. It's a hit and miss thing and depends on your personal taste in how you present your art for public viewing and how worried you are about some little sprat claiming your work as his own to his friends. (I'm using the masculine 'his' as a generic, girls have art stolen and steal art too!)
Watermarks suck. Sorry, they really do. It is a difficult, win/lose activity to use a watermark, and if you even so much as send your art to one person without the watermark, you've rendered it useless, since that one person can easily spread the unmarked piece out in to the web by sharing it with their friends.. and you see where this goes. The major Pro to using a watermark is its impossible to miss, and nearly as hard to remove. They become part of the art and only the best skilled photomanippers have the skills to remove them effectively (if you no someone who alters images for magazines, that's the kinda person who can do it.) The cons are lengthy; improper placement, size and opacity (transparency) of a watermark can either make it useless or strongly hinder an art piece's ability to garner respect from its audience. Arbitrarily slapping watermarks down the center turn off almost all viewers of the art, and they're quick to move on and find another artist with a similar style who has a less possessive streak.
Hidden Text/Images one can hide text in the code of a JPEG file. The win here is no one suspects it. The lose is anytime the file is resaved from an art application, or is screen captured, the text is lost. I suggest doing this to source files, that way you always have your name on your originals. (do it the easy way, in the file properties.)
Signatures signatures throw off a few people, and in many art forms its just standard practice to have a signature on art. I strongly recommend using a stylized signature, not just some text on the corner or bordering of the image. If should fit in to the image someplace and should be unique to you, sorta like your full name or fingerprint is. (I played with signatures on my art but gave it up, personally.)
Getting Thieves After They Lifted the Art.
For me, this is the best method. Art is always going to get stolen, so we need to keep our eyes open for our work (and other's) and know what to do to get it taken down. Now, for a few methods that prove effective.
Know Where it Came From! if you're going to report art rips on DeviantART itself, know where the original is, or at least someplace that credits the original artist. If you can toss this sort of info in to a rip report, it makes the rip report more credible and more likely to be completed in a timely fashion (and well, completed at all.) Handy Hint: if its famous art, art.com has just about everything by respected artists and photographers that exists and categorizes by style, artist, and can be searched by partial titles, etc. wikipedia.org can also be handy if you know the original title or artist in helping find a website that credits them to the specific piece (one can use wikipedia itself if the art piece has its own article or is present on the artist's wiki entry.)
Be Aggressive with the Rippers. believe it or not, you don't need to profit monetarily (money) to be prosecuted for stealing art! Representing an art piece as your own when it isn't is an act which can be prosecuted in many countries, and can carry some mean punitive fines in the right circumstances. Age also will not protect the art thief, some countries will try minors as adults, or shift financial responsibility for the minor's acts to their parents (and when I got arrested as a kid, let me tell you, having to face my dad after he got the fine was a lot scarier then having to pay it myself has ever been, and I've paid some stiff fines in my day!) Don't be afraid to act like you know more then they do.. you probably do, or can at least BS your way through it.
Send Them a Warning, Then a Bill. email the ripper a warning, or the website hosting the rip, notifying them that the rip has been spotted and that it should be taken down otherwise further actions to have it taken down will be taken. Give them 30 days to respond. No response? Send them a bill, a reasonable bill! Find out what the average running rate on the art piece might be in terms of royalty (if they're selling it, or have used it on a commercial piece) do the math on a reasonable estimate of how many copies might have been made or may possibly be purchased, and put it all in invoice form in a word document and email it with a firm demand of payment (no cussing, that makes you appear juvenile, and will get all your efforts to have the art removed ignored.) usually, an estimate between $500 and $5,000 (USD) is enough to spook them and still sound justifiable in small claims courts.
The Next Level Ignore them! and go to the company that hosts their 'art'. If this is another art community (a website they don't run themselves, such as DeviantART) then send them a notification of the rip, a link to the original with proper credits, or offer to provide proof that you are the original artist, and demand prompt removal. Most of these communities act quick (deviantART being an exception, as reactions can be slow given the size of the community.) and will remove the art, and possibly the 'artist' themselves (ban time!) If it's a personal site, go to their host and approach them the same way that you would an art community. They will demand the person removes it, and often will suspend their website or cancel it depending on how they react. Hosts hate liability, and they can be held liable in a lawsuit if you contact them first and nothing happens between notification to them and a later court date. (deviantART can even be held liable if such proper emails are sent to them and the reasonable time span according to US/California law is allowed to pass between initial contact and the filing of a dispute with the courts. This is generally regarded as 30 days, but 60 days looks even better to a judge. Again, despite what any contract lawyer will say, terms of service that 'offload' liability are bogus and are not honored in court whatsoever, so if the art is on a website or hosting company with such a liability waiver, ignore it, they can still be named and held partially responsible in court.)
Find out who they really are. If possible, find out their real name and address, and start in with the certified mail. The content should be typed on plain white paper and mailed in plain white envelopes (if you want to scare them, add a blank blue outer sheet around the invoice, request, etc. this looks legal but is not an illegal act of impersonation when used all alone.) don't be afraid to send copies to the websites and web hosts as well, physical mail looks even better in court, and the only proof is a copy and a certified or guaranteed delivery receipt from the post office. (certified is best, it gives everything an air of professionalism that can be critical in these situations.) Helpful (fun!) Hint: if they own a domain, do a WHOIS search using either whois.net or networksolutions.com/whois (or another, depending on if they have a country specific .xx/.xxx not only will this often give you their name and mailing address, but their phone number. Use this at your own discretion and means, I'm not endorsing harassment as that can actually get you in to legal trouble!)
Save Your Sources every source file you make, PSD, PNG.. etc.. keep them all. If you really love your art, rip CDRs or DVDRs of your stuff Quarterly or Annually and mail it to yourself. ( I recommend three separate copies, certified) and don't freaking open them for anything! These are "poor man's copyrights" and are time tested methods of providing proof in court. I personally even go so far as saving major "version" changes to separate psd, png and pdf files (and some word docs since I write too) that way there isn't just the latest version, but the whole history to provide particularly convincing proof.
Hidden Signatures Hide signatures in the artwork by incorporating a unique, stylized signature somewhere in each art piece. The idea of these is they are hard to spot unless they're pointed out, and make great court room dramatics when you ask them to identify the signature, and they fail to do so when you can.
Other's Artwork Ripped?
Well, tell them so! They either are already well practiced in the art of combating theft, have retained a lawyer for such purposes in the case of professional, successful artists, etc. some don't really care, too. (I used to get all huffy, but now I fall in 'don't really care') Don't expect much more then a quick little thanks for the notice though, these are artists after all, and some have pretty weird personalities!
Be prepared to be ripped, it happens to almost every artist as they improve their style and skills. Its best to be calm, collected and patient; removing rips can be a time consuming process that takes anywhere from weeks to months, and legally, rippers have those months to remove their stolen wares (though, if they're profiting, they are liable to pay you for past sales and sales up until the removal of the rip or the sealing of a deal to get you proper payment on the work. Tell them that in all communications, too!)
So, go out, catch some rippers, and have a little fun doing it too! These people can be very fun to mess with, just remember that when you're talking to them, always seem professional and sure of yourself, and don't be afraid to pay for a little paper and stamps!