Regular people know the difference, less-educated ones don't... or there are always those that would sue a company because they can... they are equally prevalent.
If someone is posting a liability disclaimer or a license agreement, but then misuses it... well, you can't defend yourself against theft. But to suggest that the answer to the problem is No license agreements is also silly.
It goes to a more fundamental issue - people need to grow up. The internet is a lot of fun, but don't assume you can just type whatever you want and not be accountable. Don't think every competition or community is just hobby-fun. You are still You on the internet, even if you think you're anonymous behind a cool nickname. And people who create web businesses are accountable to what goes on there - both to their customers, as well as ISPs, software providers, and the community within which they live and work.
Btw, it's the same attitude that people display about downloading music or software. "Gee, wouldn't it be cooler and mellower if it were all free?! I should be able to safely display my artwork everywhere, no one should be allowed to touch it... but I want that music for free."
Life is a series of agreements, both verbal and written. You can do two things: either understand that and accept it and honor it, or you can complain about how uncool that is.