Facebook is once again finding itself under investor scrutiny after a U.S. security researcher uncovered a flaw in its "like" system which appears to be responsible for liking sites an unintended number of times. Although Facebook has pointed to a feature glitch as the indubitable cause, some cynics believe Facebook has much to gain by padding its social graph via means of "Like fraud".

Researchers found that sending a URL to a friend via Facebook's private message system would add two likes to a page instead of just one. That clearly shouldn't be expected behavior. Comments left on Facebook posts also add to the total number of likes, which is actually by design. Some users find the sincerity of such a practice nebulous at best, however.

Confirming the discovery, Facebook said, "We did recently find a bug with our social plug-ins where at times the count for the Share or Like goes up by two, and we are working on fix to solve the issue now."

Facebook reiterated though that some behaviors will generate likes without explicitly liking something, such as messaging a URL to a friend. On Facebook for Developers, the BBC points out though, there are actually four ways to generate likes. However, only one of those methods actually requires users to click a like button. The rest are done behind the scenes.

Last month, the social networking icon kick started an intitiative which intends to fortify the integrity of Facebook's likes and shares. Amongst the improvements, automated tools were deployed with the intent of deleting disingenuous likes that were determined to be purchased or originate from malware or compromised accounts.