Though not a USPTO specialist or copyright attorney, but just a lowly dweeb who uses a lot of software for business AND pleasure and creates some work product that may or may not be sold at some future date (it's hard to differentiate or keep track when you're as sloppy a record keeper as me), End User License Agreements (EULAs) strike me as being almost unenforceable except in blantant examples I wouldn't consider doing even IF someone paid me, i.e., reverse engineering, relabeling or bundling proprietary software and selling it (herein referred to as Big No No's) unless you obtain a commercial license and written consent to perform a Big No No.
At most, you risk getting a perfumed note filled with flowery phrases from an attorney that essentially requests in the nicest of nonconfrontational terms that you consider pulling down whatever it is his client claims is his or a group of ninjas will dismember you and your family and feed you all to pit bulls in Michael Vick's backyard.
Of course, if there's a clear and present danger (say, hidden watermarks or digital IDs), or an unmodifiable script (or even a script you CAN modify but which produces an end result close enough to the original that could be identified by the owner in a court of law), then failure to obtain a commercial license can haunt you in two ways -
a) disgrace if your client learns you're in violation with something you sold them when a cease & desist lands on THEIR desk;
b) a potentially costly lawsuit if a cease & desist ends up on your desk along with a big bill because your profits or noteriety make you a big fat target.
Most of the software given away here comes with a single-seat noncommercial license, and has a fairly secure wrapper that makes selling it under your brand or distributing a bundled copy to others in your office or on Ebay impractical if not impossible. Any work product you create from said software that doesn't pack some sort of previous owner's identification (copyright or watermark) is virtually impossible to identify, so it's doubtful any vendor will point an accusing finger at you. Who's to say which image editing or music conversion or flash video software was used... unless it carries a tag you don't know about? (e.g., in the GIF comments box, or a script remark - "made by Joe.com", or a readily identifiable presentation shell like for a website photogallery or Ebook, or a web beacon that phones home ala LoJack)?
IMHO, EULA's from small vendors or independent artists work on the honor system, and realistically, only those amongst us who actually produce something extremely unique that goes on to become sensationally popular are likely to be caught and outed and fed to pit bulls. If you're one of the lucky ones who does become successful off a particular piece of software, then you buy the bloody software as GAOTD and the vendor want... and give 'em glowing attributions.
If you're creating something on spec to show to a client, or just removing red eye or otherwise modifying a photo or creating a texture you'll use on a web site or in a book or something, it doesn't matter much... unless you have a very guilty conscience. (in which case you buy the bloody software) OTOH, if you rip some custom music off one of the games given away and package that with your own product and sell it, you clearly demonstrated intent to violate EULA and may the devil have mercy on any parts the pit bulls don't eat.
I'll let you all know if I get a polite letter from an ambulance chaser telling me my comments & opinions are in fact dead wrong and he's got a pit bull cage with my name on it.
