A proposal to legalize marijuana is the first idea on the White House's online petition site to gather enough signatures to break the threshold required to receive an official response.
The White House has promised to evaluate and issue a formal response to any idea that receives more than 5,000 signatures within 30 days. Visitors are free to offer their own proposals.
The first proposal to reach that limit asks, "Isn't it time to legalize and regulate marijuana in a manner similar to alcohol? If not, please explain why you feel that the continued criminalization of cannabis will achieve the results in the future that it has never achieved in the past?"
The seventh most popular petition, with 390 signatures, urges the president "to formally acknowledge an extraterrestrial presence engaging the human race." The petition claims hundreds of witnesses have testified to the existence of aliens visiting Earth.
The White House has not yet issued a formal response to the marijuana legalization petition.
Drug legalization questions have also dominated Obama's YouTube question-and-answer sessions.