Modern Dilemmas

What do you do when someone you are fairly sure that you have never met sends you an Orkut friend request?

In my case, you wonder "wow -- are (non-brazillian) people still using Orkut? I thought that was soooo 2003...".

This being the connected interweb, the mystery non-friend does also list as a friend someone that I met once in a pub in Cambridge. This still does not convince me that I know this person. Not that any of this matters, but I suppose I just ignore the request - or should I actively deny it? I suspect it does not matter very much.