Other people's children

I had a conversation with a friend of mine yesterday about other people's kids.
Her son is 9 and in Boy Scouts. She told me about a certain boy coming over for a sleep over and how the boy stole money for a fundraiser and when she brought it up to the mom, the mom pretty much denied it and blew it off. I would have marched my ass to that lady's house with a baseball bat and a friend dressed up like a cop to get that shit back. With intimidation of course, not violence.
Luckily I don't have to deal with other people's children as much. My son hasn't made any outside of school friends that aren't our friends' kids. Mostly our friends raise their kids similarly to us so we don't have huge issues.

We did have this one couple who brought their kids to our house for a barbecue and the kids proceeded to rip Hayden's room to shreds while the parents didn't check on them once.  They took lego creations apart that I had carefully put together for him and tossed the pieces in the air like they were dollar bills at a strip club. It's been a couple years and we still haven't been able to find all the pieces to one of the sets.

The worse experiences we had with other people's kids were with our old roommates kids. He would sleep until 2pm and his kids would run around the house all weekend unless I got up and watched them. They destroyed some of my candles, some of Hayden's toys, and ate most of our Halloween candy one year tossing the wrappers in random places all over the house ie: behind the toilet, under beds, in between books on the bookcase, etc. We tried to get our roommate to take responsibility and discipline them, but he was a lazy jerk and didn't have any respect for us.
I also witness a lot of rude kids at the parks. There are kids in our neighborhood who play at the park every day until dark and never do I see their parents around. I've had to tell kids to watch their mouth around my son who were the same age or just a couple years older. This one ten year old girl drops more F'bombs  than most musicians I know. Another kid walked into our garage and stole our skateboard. We didn't know till a neighbor saw him riding around on it and it had a bipolar sticker on the bottom.

I know my son is not perfect. He battles with being a picky eater and won't eat new foods at other people's houses. We try to work on that every day.

Like Louis CK, I'm amazed at the lack of responsibility people take for their children's behavior these days. I believe a lot of parents are too wrapped up in their own shit to care for how their children behave around other kids and other adults.
Take the damn time to teach your kids manners, and PAY ATTENTION to what their doing. It's not other people's responsibility to teach them manners.
Also, kids learn from example, if you're a jerk and lazy your kid is going to be a lazy jerk. If you sit on your ass yelling at them all day, they're going to be unhappy and will probably act out at school or with other kids. If you don't teach them respect for other people's things they'll throw legos around my house like a jackass.

Here's 25 Manners Every Kid Should know by the time they are 9

Dr Sears' 7 ways to teach children manners.