One oddity of the current legal situation remains that the U.S. government needs some kind of court-approved warrant to intentionally eavesdrop on the telephone or e-mail of a U.S. citizen suspected of involvement with al Qaeda, like Anwar al-Awlaki. However, using a drone, a missile, bomb or military raid to intentionally kill that same person requires no approval from the judicial branch.

Josh Gerstein, "Obama: U.S. seeks 'due process' in drone strikes,"
Politico (Sept. 7, 2012)

Hm, now that you mention it, that does seem odd. It almost seems like we should have some sort of rule preventing that.

The quotes around "due process" in the title are because that phrase was used by the president in a recent interview. The fact that he was also making "air quotes" at the time he said it is purely coincidental.