Sen. Marco Rubio Gets 'Three Billboards' Treatment, Trolled for Florida Shooting

Sen. Marco Rubio is getting called out over gun control -- in the wake of the Florida shooting -- in a way that would make Frances McDormand extremely proud.

Three billboards are parked near the senator's office in Doral, FL ... each clearly referencing Wednesday's school shooting in Parkland ... and asking Marco Rubio why there's been no gun control reform.

The billboards replicate the Oscar-nominated film, "Three Billboards Outside Ebbing, Missouri" ... where Frances' character puts the heat on a sheriff to solve her daughter's murder.

The real-life trolling of Rubio was organized by the activist group Avaaz, whose deputy director Emma Ruby-Sachs says, "Florida has notoriously lax gun laws, and Rubio, who is supported by the NRA, has never attempted to reform them."