Linked posts in the review, news, and discussion sections that promise "NO SPAM" video, pre-aired video, and other false claims often ask you to provide your email address or other personal information to view the video.
DON'T DO IT! Don't give these spammers revenue, and they won't stick around. Don't fill out their surveys or install their malware, viruses, or toolbars.
There are plenty of free videos out there with no obligation to view them.
Feed the trolls and they will stay forever. You can help fight spam by not supporting their sites.