Three Percenters
The Three Percenters show up with weapons when they think that the federal government is abusing someone.  For example, Three Percenters showed up to a ranch where a man had said he would not pay federal grazing fees for his animals.  They said they wanted to protect him.  Three Percenters also show up to liberal and left-leaning events.  Sometimes they are there as counter-protesters.  Sometimes they say they want to "monitor" the liberals.