If you put a video up on YouTube, you should be prepared to face some hatred in the comments field (most people expect praise, hence why most videos are posted). I'm guessing in about 99.9% of videos with over 500 views, you will find a horribly offensive or inappropriate comment.
"Some of the comments on YouTube make you weep for the future of humanity just for the spelling alone, never mind the obscenity and naked hatred."
- Lev Grossman, Time Magazine 2006
This type of open criticism is worrying to companies that want to go viral; but it shouldn't stop them. There is the option of of blocking comments, but by doing that you would also block positive comments and important feedback.
Mike Wesch gives his formula for obscene comments below.
anonymity
+
physical distance
+
rare & ephemeral dialogue
=
hatred as public performance
+
physical distance
+
rare & ephemeral dialogue
=
hatred as public performance
Message to companies putting a video on YouTube: don't fear the negative comments. Most importantly don't take it personally and lash out against people, unless of course, you want to unleash The Streisand Effect. But I wouldn't think so.