Facebook could be used to discover if people are serial killers.
Researchers from Sahlgrenska Academy and Lund University in Sweden found that status updates which could indicate that a person is a psychopath or shows some neurotic or narcissistic tendencies.
In a report in the scientific journal Personality And Individual Differences with the catchy title The dark Side Of Facebook, the researchers say that if you do not want to be outed as the next Ted Bundy, do not put any status update which mentions prostitutes, decapitation, pornography or butchers.
Not having a Facebook profile could also be a bad sign. Theatre shooter James Holmes and Norwegian mass murder Anders Behring Breivik did not have any Facebook profiles.
Some bosses have gone on record as thinking that a lack of Facebook could mean the applicant's account could be so full of red flags that it had to be deleted.
Other personality traits which can be found in a Facebook sweep are those with narcissistic personality traits could emphasise their own good characteristics. These people are self-absorbed, self-glorifying and have an exaggerated confidence in their own abilities.
Neurotic personality traits can be found by looking at status updates and by how many friends you have on Facebook and how often you update your status.
Facebook users with extrovert and open personalities generally have many friends on Facebook and update their status more often than others.
Machiavellian types are cynical, emotionally distant and unaffected by morals. They deceive and manipulate people in their surroundings to gain advantages, the report said.
The report tested Facebook users with a scientific questionnaire with questions that test extrovert, neurotic, psychopathic, narcissistic and Machiavellian personality traits. They were also asked to send in their last 15 status updates.
The contents of the status updates were then studied with algorithms for latent semantic analysis, which is a method for measuring the significance of words.