I assume the video's are not hosted here, but reside on YouTube's servers. Right?
The only thing youtube would see is your IP address, it's no different than if you visited the page itself via a link. To gain access to who you are they would have to get that information from your ISP. I don't know but if you have a youtube account they may be able to track the videos you see here even if you don't view them if you have a youtube account and are logged in.edit: Just so its clear no information that I have such as your usernmane is passed from this site to youtube.
While on the topic if Viacom wins this lawsuit its going to have profound effect for sites like this one or any other site that allows people to upload material whether it's text, images or video. As it stands now Youtube, this site and others are covered by the safe harbor provision.
The safe harbor provision limits liability to sites that allow uploads, for example here anyone could upload copyrighted text, images or video without my knowledge. Much the same like a grocery store can't control what is pinned on their bulletin board I can't control what is posted here. When someone uploads copyrighted content to youtube or anywhere else Viacom or whoever owns the copyrights can send them a DMCA notice of the violation and they have to remove it promptly.
Viacom instead wants youtube to be held liable for content if it's posted at all, if they are successful any site like this one would be also be liable for copyrighted material. The only way to prevent that is to premoderate every post before its made public which would be a huge task. There's other issues as well because I'll have to make a determination as to what is or is not "Fair Use".
If they are successful a lot of sites like this one may simply vanish, especially ones making very low income or no income at all because it simply will not be worth the risk.
It's just another example in a long list of technologies that mass media companies have attempted to squash through the years. If it had been up to the MPAA and the RIAA you wouldn't have any device that allows recording. Ever hear of the DAT format or a CD recorder? One of the reasons these devices never it made it to the consumer market is because they have a heavy tax on them making them very expensive. Even the media itself they use, if you ever have seen a a CD labeled audio CD that's actually a special CD that will work in standalone CD recorders, you can't use a regular CD in them. The CD itself also has a tax making them more expensive. This "tax" goes right to the RIAA, so you're paying the RIAA the right to record on theses devices.
They attempted to do the same thing VHS, MP3 players/recorders, and the CD/DVD burners in your computer....
Sorry for the off-topic but.