Losing data connection isn't always a sim-swap attack!

Here's something that happened to me like 5 years ago, then happened again today, that you should spot immediately if it happens to you. My phone's mobile data stopped working: I only noticed when I went outside since at home I use wifi. I thought perhaps I'd been "SIM swapped", when an attacker calls your mobile provider and convinces them to transfer your number to their phone (so they can use your number to hack into your email etc and steal your bitcoins): but after calling my provider, that wasn't it.

In fact it turned out my phone worked fine for calls, just no data.

After various experiments with Tiffany from tech support (great accent - "Is your wahfah on?") we determined the problem:

I had accidentally clicked the option to turn off mobile data. Probably my ear did it while I was talking to mom.

Clicking the option again fixed it. Classic PEBKAC ("problem exists between keyboard and chair").

Embarrassing to go through the same whole rigmarole five years later, with the same ending. So yeah if your mobile data seems to die on you, check that.

Ultimately, if you are going to get sim swap attacked, then the best practice for protecting your crypto is storing it offline in cold storage with no passwords in your emails etc.