You've probably read some of the cries for gun control and the stat of "more than one mass shooting a day" happening in the US. To see this propaganda, you'd think that people walk around with Uzis, randomly opening fire all the time. You've probably had this map indignantly posted at you in response to something you said about guns on social media.
But, you see, the map is BS. It's a big old truckload of baloney sandwiches, steaming in the sun. It's a manipulation that is being used to frighten people into thinking they'd be safer if none of us had the tools that we need to protect ourselves.
These terrifying dots are not all brazen shoot-outs in malls or movie theaters, during which someone takes out as many people as they can. But that's how it's portrayed. It's posted without any real criteria except for the fact that it is incidents in which 4 or more people are shot, including the initial perpetrator. (A reader pointed out that these dots indicate shootings, not deaths in every case.