So how many time can parents leave their child HOME ALONE?

So how many times can parents leave their youngest child HOME ALONE during a vacation without having child services called? So far its been twice. OK I could deal them leaving him HOME ALONE once but they left him HOME ALONE 2 many times. It's really starting to effect the little guy, his name is Kevin and the first time they left him he was 8 and 2nd time he was 9. He lives in a really nice neighbor hood but you know burglars hit the streets during the holidays. He is quite smart, very mature, and responsible. Lets hope the same thing doesn't happened that happened last year, let him get on the wrong plane. Should I report them?