WASHINGTON - The Secret Service is investigating an online survey that asked whether people thought President Obama should be assassinated, officials said yesterday.

The poll, posted Saturday on Facebook, was taken off the site quickly after company officials were alerted to its existence. It asked respondents "Should Obama be killed?" The choices: No, Maybe, Yes, and Yes if he cuts my health care.

The question was created by an independent person using an add-on application that has been suspended from the site.