For me it’s the paranoia surrounding webcams. People outright refuse to own one and I understand, until they go on and on about how they’re being spied. Here’s the secret - unplug the damn thing when you think you won’t use it or haven’t used it in a while.
They, whoever it is, can’t really spy on you on something that’s already off and unplugged!
Saving a picture and posting it somewhere.
I see people making screenshots of their whole phone’s screen and posting them just to show a picture. In reality, maybe 90% of the time, if you see a picture on the screen of your phone, you can save that picture, with no pointless information around it, no black bars and so on. Even if that’s not possible, Android for example has been doing something from the recent apps screen that lets you extract a picture from an app’s screen - and that’s arguably even easier than doing a screenshot.