In this situation, I would not try to guess whether they're "peaceful" robbers or if they'll kill someone. My wife would make a beeline for the door (she's good at that) and I'll run behind the metal door post and start shooting from that cover. Most of the young "homies" have never been to the range to practice. They are poor shots. A few are crack shots just back from Iraq (our government has been desperate for recruits, so they have been "overlooking" some criminal records). I would shoot the most confident one (best shot) or leader first. I'll save the ones who are sitting next to other CHL carriers to be shot last (they might come to my aid, but as I've read on this forum, probably not). Once one of them go down, the others will flee. Thugs are lazy. If they weren't lazy, they'd be gainfully employed, right? Shooting it out for a cash register till is hard work. Trust me, they'll flee. Faced with combat stress, people will either freeze, fight, or flee. The fighter is probably the leader, that's why he gets shot first. The ones who freeze with a gun in their hand will be shot next. Thugs who flee will be spared. So, although it seems like you're fighting enormous odds, with the proper tactical mindset, you're only fighting ONE perp. In a group of 6 perps, only the leader will probably fight, but the others will either flee or freeze. If your family is safely out the door and you have cover behind a metal door post, then you could effectively defeat a group of 6 perps.
Some poster mentioned that he was afraid that he'll accidentally hit another diner. In such a situation, most diners will be underneath their tables. Firing head shots at the only people standing upright, the perps, will place the shots far enough away from the diners so that even if you miss, you won't hit a diner.
I am a big chicken and I am not a brave man, HOWEVER sometimes a MAN has to do what a MAN has to do. A real man would defend the innocent against thugs. Plus, if they're in the open waving guns around and you have cover, YOU have the tactical advantage even though you are seemingly outnumbered (seemingly outnumbered because only the leader is the fighter in most thug gangs, so you're only fighting one person).
I once knew an elderly Chinese man who held back THOUSANDS of armed Japanese with just a musket (not even a gun!). The Japanese have a rule that they cannot allow enemy soldiers to be left alive behind their lines, so this Chinese gentleman and his buddy were going to fire a shot from old muskets then hide. While the Japanese were looking for them, their families will evacuate their village and hide in the mountains. His buddy chickened out but he fired a shot and hid. It took the Japanese hours to find his buddy and kill him (ironic, huh?). Thinking they found their shooter, they stopped looking for the shooter and left the Chinese man in hiding. Meanwhile in the hours that they took to find and kill his buddy, his village was able to run and hide in the mountains. He saved his entire family and all his neighbors. If my elderly Chinese friend can fight off thousands of armed Japanese with an antique musket, YOU might be surprised to find yourself able to fend off 6 measly "homies" !
That would be great. Hey, 
that should be our goal, having most law abiding citizens be armed and deter crime because the bgs are the out numbered & scared ones. Okay...I'm awake again.
