A question of responsibility

The Register has published an update to yet another legal action against Google, this time in Italy - "Google on trial over Italian 'defamation' vid".  Some background:

In September 2006, someone posted a three-minute cell-phone video to Google's Italian website in which four Turin teenagers make fun of a classmate with Down's Syndrome. And in July, after two years of investigation, Italian authorities filed criminal charges against four Google execs: chief legal officer David Drummond, chief privacy officer Peter Fleischer, an unnamed London-based video exec, and chief financial officer George Reyes, who has since left the company.

What's interesting is that within a day of a complaint about this video reaching YouTube, the viseo was taken down.  So where does the responsibility here lie?  I suggest the perpetrators of the bullying, and those who posted the video are the villains of the piece, not Google executives or YouTube operatives.