I confess it bothers me when people record without permission - particularly when those recordings are then spread around. If people ask, I usually say "yes," unless there is a particular reason (ie, the performance was not up to my usual standards).

For performers with CDs, recording can get in the way of CD sales - which often (depending on the level of professionalism) pay for either hobby or rent. Some festivals and venues record everything as a matter of course - which is fine, for archival purposes. I've even known performers who have gotten wonderful live records out of that kind of situation - but if it's ever going to see the light of day, permission really should be sought.

Photos I don't mind, though flash photography during a performance can be distracting. But my art is the music, not my looks, and I like to retain a little artistic control over the former.

Dan