I've encountered all except no.1. I find them so damn funny. It's like a lame attempt to scam me.

My favourite one is the paypal one asking me to for my password because someone was trying to logging and they're asking me to reset it. I love that one. It's such a resonable attempt except for the fact that they didn't mirror paypal's site well. And paypal would never have an IP as their domain. In addition to that, paypal wouldn't ask for such information without using https.

That's really a scam for people not familiar with the internet. However, I keep an open mind because I wouldn't want to get caught because I'm naive.