So you go into Settings — and the phone talks to you in the voice of someone else's sysadmin

Not to you, mind. It didn't even say hello to you.

MDM is when a device is registered to a company. They push apps remotely, set passwords, set restrictions. And in the worst case — they simply turn the phone into a brick. Because on paper it's not yours, it belongs to some company called Romashka that wrote it off three years ago and forgot about it.

Checking before you buy is dull but ruthless. You go into Settings — General — VPN & Device Management. If you see a profile, that's not a tick, that's a red warning light. If they'll unlink it — you can take it. If they won't — knock the price down to the value of a paperweight.

Sometimes the menu is empty, and the surprise comes out after a reset. There's only one honest way here — a diagnostic with a check of all the locks. It's not a tricky thing, but you need to know what you're doing. We only say thank you to such cases.