The purpose of this meme campaign is to make a joke of using symbols on maps and to suggest that it is arbitrary. "Oh, LOL, Outback Steakhouses make a pentagram!" people say. Then someone shows them a pentagram in DC connecting pedophile hotspots and they're conditioned to think it's random noise. As people are generally not that intelligent, this serves to distract them from realizing that maybe it's not so random. Any time you see a story gain "viral" attention you can bet it's being done for a reason.