xnavigator - 12:18 am on Jan 24, 2011 (gmt 0)
I don't think a bot can recognize a content farm between a "normal" website.
The only common factor between content farm that a bot could find is:
large differences among the topics covered
So if a website treats too many topics would be considered a content-farm, but this problem could be easly avoided by buying more domains and place 1 topic for domain.
So I think this is one of the case where google will use humans to filters it :D