The Toronto Sun has the rundown on the current theories:
The mystery of missing Malaysia Airlines flight MH370 has spurred a list of conspiracy theories — both sound and crazy. Here are the top 5.
1. Terrorist attack
After reports surfaced that two passengers were flying using stolen passports, and authorities were "examining additional suspect passports," the immediate assumption was a terrorist attack. Investigators told ABC News they are "not discounting" the possibility, but have no evidence of a bombing on board.
2. Spontaneous explosion
After more than 50 hours of searching the missing Boeing B777-200's ocean path, there is no evidence in the water that would suggest a crash. More than a few investigators have suggested the lack of debris could mean a sudden chance explosion and that the plane may "have disintegrated at around 35,000 feet."
3. Trapped in Vietnam
Oil slicks were spotted off the coast of Vietnam on Saturday, and even though investigators said they were not left by the missing plane, one conspiracy suggests hijackers are now holding passengers and crew hostage at an abandoned Vietnamese airport. This theory was seconded by some friends and relatives who say they their loved ones' cellphones were ringing unanswered even days after the plane disappeared, proving, they say, the phones were still functioning.
4. Biometrics link
Some have suggested a link to makers of biometrics passports. Last March the newly formed Secure Identity & Biometrics Association (SIBA) released a statement arguing the need for biometric passports and borders to be implemented for travel safety. With reports of the stolen passports, the SIBA released another statement about how "cost-effective" and "extremely fast," biometric readers are to "building seamless convenience ... and safer skies."
5. Aliens, Hollywood hype and secret U.S. aggression
Some fringe theorists online have dug out the old faithful alien abduction theories, while others blame a secret "U.S. carrier strike." One of the more fantastic conspiracies is that it's all just a Hollywood promotional stunt for the remake of Lost.