The First Amendment protects the media or web messenger, but the message can have murderous consequences.
Experts say recent attacks back up the findings of a controversial Department of Homeland Security report.
The man charged with murder in the Holocaust Museum shooting gave clear clues about his hatred of Jews on the Web. But it's hard for law enforcement to filter anger from murderous intent.
The attack, which killed one, is the third fatal shooting by an extremist in 10 days.
As he landed in Tel Aviv, Pope Benedict XVI spoke of need for a 'just resolution' for Israelis and Palestinians
The latest stops in his Mideast tour included the rocket-besieged Israeli town of Sderot and the West Bank town of Ramallah.
Socially minded outfits use the company's globe-mapping software to illustrate plights of refugees, others in need.