Of course this assumes that the cafe has never changed from the default password. It wouldn't work on my combo modem/router supplied by my cable internet provider. Each unit has its own unique default password based on its serial number.

10.0.0.7? that's kind of a strange ip address.

Some routers will auto-switch to a 10. subnet (from the typical 192.) when there is either mishap with the router config/collision, or possibly repeat disconnect from the ISP. Some folks set this by design. Google can tell you the intricacies.

I won't *say* I've ever done something like this. However, it's incredible how many local coffee shops/independent establishments just do not change the default config of a router. I'm genuinely dismayed how this utility, appliance and overall service continues to confound people.

Your privacy isn't that, folks, just be careful!

He probably blacklisted the MAC address, which basically means that dude's device will never again be able to connect to that router. (Two assumptions there: 1. The business will never change settings or factory reset the router, very likely considering they didn't even change the default login. 2. The guy doesn't know enough to spoof his MAC address, also likely by sheer probability.)

I don't disagree that it is deserved, but on the other hand, he's inflicting a fairly permanent punishment on the dude on the behalf of the business, without consulting them about it. If he's a regular that was just having a bad day, he might pester them about why his wireless isn't working any more and they won't know the answer. Or he might decide to stop going there.

If that's how the cafe wanted to deal with him, I'd be all in favor. But it should be their decision. So I hope the guy informs them about what he did and offers to A) train an employee to do the same (plus changing the router password) and/or B) undo what he did IF they want him to.

*Internet

Not really. The reserved ranges for internal addresses are:
10.x.x.x
172.16.x.x - 172.31.x.x
192.168.x.x

I have no idea what happened, but I think I like it.