Is IP Check a privacy policy violation? Anyone can work out what IP range some users were coming from by a two second log check.

They do it all the time, they just don't broadcast that fact everywhere.

I would think that it is (blissy explains it below).

I don't think that IPs are private. However, some information that can be gained from IPs in some cases can be private. And combined with other information can be very invasive.