Technical assistance

Someone who calls themselves 'Supreme Thatcherite' posted a link to a racist video in commenting on my last post.

I've deleted it, but wondered if more IT literature readers could tell me whether there are any simple and quick ways of e.g. finding their IP address or otherwise identifying them, via Google Analytics or otherwise?

Obviously, anyone who voluntarily chooses to go by the name 'Supreme Thatcherite' is already in a pretty bad way...