[p0w3n3d]

TBH phones in Poland allow to call you "from" an arbitrary number (i.e. display it on your phone). Also send SMS with arbitrary source.

This is being used by scammers who call you and tell they are from police bank etc

[allthetime]

I constantly get scam calls from numbers that are very similar to my own in Canada. I assume this is an attempt to look like a normal trustworthy number.

[lxgr]

This works in many countries, since the signalling protocols historically assumed a trusted small set of participants, not unlike email – with similar consequences once those assumptions became less and less true.

[baconhigh]

it’s common for cheap esim providers to route data etc through cheaper data exits, i imagine this is partly why.

(I recently purchased an esim and was surprised to see it exiting poland instead of the country the mobile provider (Bell) resides in)

[kakacik]

I've worked a bit on the app which calls major telco provider directly. It was a basic web service call, and sender could be entered as anything. This is basic property of cellular networks, no more safety than say standard email.