It is usually obvious in person when a nickname is just friendly banter and when it is designed to ridicule. In print and on the internet it is not so obvious... and MOST names for political figures and others whom you don't know personally are meant to ridicule.

I think, after 10-15 years of this forum, I see nicknames used by UK members more often and with sharper intent.

I personally tend to avoid them unless it is clear how I mean them.