I have never had a run in with an established performer. Every "name" act that I've had the priviledge of meeting (and I do consider it a priviledge to talk about music with musicians more talented than I) has been friendly and encouraging in every respect. This is one of the things that I love about the folk scene - there are no big egos, and I've never seen an act that's considered itself above talking with the punters after the show.