I think you also need the Steam client, which is free to download and use.

I am also in favor of being able to report comments, users, and forum posts as spam. The advertisements for a certain massively multiplayer online website being spammed on videos is incredibly annoying.

If it's not already, it should be made clear in the Terms of Use that spamming the same comments on every video, to put it nicely, isn't @#$&ing cool.

If, for some reason, reporting users isn't viable (and I can't think of why it wouldn't be, except maybe lack of the technical knowledge required to do so), perhaps a limit on the number of comments made per day could be enforced. Or perhaps don't allow users to comment unless they've posted a video themselves or something.

Something MUST be done to prevent this from happening, or else users are going to get more frustrated (not just from the spam, but from the lack of action towards the spammers) and eventually stop coming to the site.