If anyone wants the link I'll go fetch it. Here's the part that came up on a railfan forum after someone had a photo used by one of the companies:

By entering this Contest and uploading your Submission, you irrevocably grant to Sponsor and their agents the unconditional and perpetual right to post, display, publish, use, adapt, edit and/or modify such Submission in any way, in any and all media, for any purpose, without limitation, and without consideration to you.

Then they claim infringement and illegal use, call an attorney who says, send in a cease and desist request.

Standard contest boilerplate and why I won't enter any of them. They have the right to use your work, edit or whatever they want, just because someone entered. This isn't for winners only, it's for all entries.

I once read the fine print on a USA Today travel photo contest.  It gave them full ownership of all submissions.  Basically a giant copyright grab.  I've stayed away from all contests ever since. 

Yeah and another one required the email address and I started getting spam from about a dozen places a day, it was some win a 5D giveaway, get a free entry for everyone you sucker in refer.  Blocked that and dropped the site immediately. They must work on selling lists and page views.

But one of my favorites was a humane society animal photo contest. Paid entry, they owned all the entries and you got a spot on the calendar they were going to sell for the next year. Nice donation fund raising idea, but it's not really a contest! It's a way to raise funds, and what better way than animal lovers who take more pictures of their pets, than their kids. (for good reasons from my experience!) 

Best ever, and I'll repeat this some day because it was so funny. Back in the days of film, the 60s. I was playing with a pebble finish f5 paper for printing. Doing things like industrial and construction. Some "friend" of a friend said, can I borrow a couple of those to show someone. Me being a dunce, said, oh sure.

Aside from never seeing that guy again, someone else who knew him said, he stole the photos, had them mounted and entered them in a contest as his work!

OK kind of flattered, I wonder how he did, but what a f'n cretin!

Contests are mostly for the promoters, advertising agents and I'm sorry to say, only for feeding egos.