SWATing, for those of you who don't know what it means, is to call the police and misrepresent a situation using words like "active shooter" so they respond with maximum force. It seems that some (about 5%) of commenters on places like the Facebook page for Moms Demand Action, or gunfreezone.net (no, I will not link to them) are actively advocating that you call the police and "misrepresent" (e.g. lie) about the actions of a person who is open carrying their firearm. Here is a nice example:
This is somewhat similar to what happened to John Crawford III, where a caller to 911 grossly misrepresented Mr. Crawford's actions, which lead the police to approach with a "shoot first and ask questions later" mindset. Mr. Crawford died as a result of these "mischaracterizations."
If you are thinking of calling 911 to report a visibly armed citizen, just to "ruin his day" and/or "get him what he deserves," all I can say is DON'T. This is one of those "sound good" ideas that isn't a "good, sound" idea. In Tennessee where I live, if you were to see an armed citizen (you honestly don't know if they are properly licensed or not) who is minding their own business and you call 911 and infer an "active shooter" situation where you state the armed citizen is brandishing his firearm in a reckless manner, or shooting other people, that is basically filing a false police report. At minimum, that is a class D felony, punishable by 2-12 years in prison. Under the right circumstances, it can be bumped up to a class C felony, which is 3-15 years in prison. It could also open you up to a personal liability lawsuit by either the person you called the police on, or their surviving family members, which is what looks like is going to happen in the Crawford incident.
So, if you get the urge to teach someone a lesson and you lie to the police, the end result is YOU end up in prison and with a hefty multi-million dollar lawsuit judgement against you that will be awarded to you after you finish your time in "the big house." Good luck with that.