Trolling on Facebook: an ugly pastime

I joined Father Frank Pavone's  Pro Life Group on Facebook http://www.facebook.com/profile.php?id=683416425&ref=mf#!/ProLifePage and I can't get over the very many ugly remarks made in this site which are directed at Christians in general and Catholics in particular. There are people who join groups for the sole reason of spewing hatred every chance they get.  I think they call  this pastime trolling but I am not sure. Correct me if I am wrong but Is it not a crime to promote hatred of individuals or a group of individuals based on religious beliefs? Why would individuals even make such publicly outrageous comments anyways? Employers now use facebook to see what their employees are up to. Oftentimes an employer will check facebook before hiring someone. It is common knowledge that the police also use facebook . So what gives? Are people stupid. It seems that some are very stupid.