Yep, something similar I discovered recently that if you sign up to Instagram with somebody's email that they use on Facebook then within a day or two you'll start to see all of their friends from Facebook whom are also on Instagram in your recommended follows. All of this happens without email verification..

Yep, I have a relatively common name and @gmail.com address. Last week, some guy with my name signed up for Instagram with my email adddress and started posting without ever verifying his email.

I reset his password and tried to close the account after he kept trying to access it by resetting his password again. Instagram support asked me to send a clear photo of myself holding up some random number to prove it was me. Nope lol.

> All of this happens without email verification

This has very interesting consequences...

Whoa... so it was around in the open since around 2013, and still not fixed? 0_0

Almost every shop does this, no verification before use. ffs, at least provide a "report not mine" function.

I've only ever seen a "report not mine" function from Google. Where else have you seen it? I am not on FB/LinkedIn/most similar ones, so I may be missing examples.