Webado, a Top Contributor from the Google Webmaster help forums posted a thread at the Google Webmaster Help forums about a "disturbing incident" they had while visiting Google.
They were at a local mall in San Francisco and noticed a "man stumbled out of a mall" where he was "under kicks and punches from security guards, and was thrown to the ground."
They even captured a video and images:
Of course, we have no idea why the security guards took such action. We do not know if he tried to steal something, if he harassed someone or if it was just all a big mistake.
But for some of these non-US residents it was a bit disturbing to see.
Forum discussion at Google Webmaster Help.