If it is TEN damn 16 year-olds or so, that's enough to be a legit threat, so you, and especially if they are threatening your family. Plus they could be armed for all you know. I'd do like koto-ryu said, try to de-escalate the situation as much as possible, but otherwise rough some of them up if necessary.
And if they're too big or too many, go hide in the house.
I heard something liek this happened recently though with one kid whose uncle was like in a gang or something, and this kid broke the windows of this one man's house and everything, and constnatly threatened his family, but told him if he did anything to the kid, he'd be in serious trouble because his uncle would get the gang on him. The guy tried with the police and all that but they didn't want to hear it after a while, and stopped providing any aid.
In the end, the guy shot the kid. He was from the military, from the recent Iraq War I believe. I think there was a big national stink over it, not sure.
My cousin, who is a totally stupid brat came into this situation too with some little kid who kept throwing rocks and gravel at her; he never said it to her, but he was being a brat one time to another friend I know (who told the kid to get lost), and the kid had said, "You know, IF you ever really hurt me, I know someone who could come and hurt you really bad." Anyhow, he made a mistake with my cousin, as she was one of those real roughneck kids, and she was 16 or 17 at the time, so she grabbed a big pile of gravel and POW! right into the kid. So of course "WAAA!! Why'd you hurt me!?" "Because I #$%#$ told you to stop $$##@^&^%$@# throwing rocks at me!!" Best justice I ever saw
(the kid wasn't injured badly or anything, just had a taste of his own medicine
).