I had a look at the Terms of Service for Flickr (Yahoo), Facebook, World of Warcraft (Blizzard) and Delicious. The question of ownership is one that requires a little more explanation. For Flickr and Facebook, anything that I create, I own, however if I upload it I grant a royalty free license to use that content to the website owner. It gives them the license to use, distribute, reproduce, modify, adapt, publicly perform, and publicly display the Content. For WOW, they own the content and the user is licensed to use it, and for Delicious the only real content is tags and URL’s so it really doesn’t apply. Having programmers in the family, I was pretty well aware of general terms of service, but I was most surprised by WOW. There are some very specific do’s and don’ts and a complete Code of Conduct which I found very interesting. The other big surprise was from Facebook, and the stipulation that you may not use facebook from a country which is embargoed from the U.S.
I do use Flickr and Delicious with students, but carefully and not in public areas, I find them very useful tools.
Here is a link to a little tool that keeps track of changes in Terms of Service for websites. I thought it was interesting.