In the latest incident of violent rhetoric against the president, an anonymous user of Facebook posted a poll on Saturday asking if Barack Obama should be assassinated.

Administrators of the online social networking website took down the poll on Monday, but not before it received 730 responses to the question, “Should Obama be killed?”

The identity of the poll’s author is not known, nor are the responses to the poll, which was posted using third-party software unaffiliated with Facebook itself. The incident came to light after the Secret Service received a tip and contacted Facebook.

Threatening the life of the president is a crime in the United States, and the Secret Service is working to determine if the poll was meant as a tasteless prank or an incitement to violence.

The incident is the latest in a series that may point to a rise in hate speech against President Obama.

Organizations that track hate speech have noted a rise in such rhetoric over the summer, particularly since Obama began pushing for healthcare reform.

The poll on Facebook seemed to be playing off the healthcare controversy, listing as its four answers: “Yes. Maybe. Yes if he cuts my healthcare. No.”

The Secret Service is investigating two other possible threats against Obama, as ABC News reports:

The Secret Service is investigating a Maryland man who held a sign reading “Death to Obama” and “Death to Michelle and her two stupid kids” outside a town hall meeting this week. And in New Hampshire, another man stood across the street from a Presidential town hall with his gun on full display.

President Obama has long been a target of threats, stretching back to his Presidential campaign. Although the Secret Service would not disclose specific threats at that time, it did admit that Obama was the subject of more threats than any other candidate.

In light of recent threats, political observers have called the Facebook poll more than a sick joke. Some also worry that, with such incidents now apparently rising, the Secret Service may be stretched too thin to adequately investigate them all. Earl Ofarl Hutchinson writes in an opinion piece for The Daily Voice:

The Secret Service says it’s investigating. But here’s the problem, in fact there are several problems. The agency may be understaffed and under resourced at least that was what it said in its 2010 budget request report back in May. The service promptly denied its own report. But at the very least Obama’s virtual non-stop appearance schedule would tax the resources of any protective and enforcement agency.

Facebook users are also weighing in on how serious a threat the poll posed, the Los Angeles Times reported: The same day it was taken down, members created a second one asking if the author of the first should be arrested.