From CNN.com: Secret Service investigating Facebook poll on Obama

The social networking site Facebook on Monday pulled a third-party application that allows users to create polls after a site member built a poll asking if President Obama should be killed.
...
The possible responses to the poll were "yes," "maybe," "if he cuts my health care" and "no."

This is appalling but not surprising.  The anonymous nature of the internet has created a culture of people saying anything without consequence.  You can see this in any comment section of any article.  It's a coarseness and disagreeableness that's carrying over into everyday life.

UPDATE 9/30/09:
From primebuzz.kcstar.com: GOP Cong. Trent Franks calls Obama "enemy of humanity"

Do they Republicans have anything useful to add to the discussion besides rabble rousing?