Mysterious graffiti appearing on the Mission Beach boardwalk belongs to a group protesting computer security practices.

People living near Mission Beach say the unusual "Anti-Sec" graffiti first appeared last week on the boardwalk. It was quickly painted over, but the stenciled words were back Monday morning.

A computer security expert who spoke with News 8 says "Anti-Sec" stands for "Anti-Security Revolution". The organization claims it recently shut down several gamer sites, as well as websites for the CIA and FBI.

According to the group's mission statement, it believes the security industry uses full disclosure to profit and develop scare tactics to manipulate consumers into buying firewalls, then overcharges for products.

The group says it believes in spreading its message through mayhem.