I'm not sure I understand many of the objections to being photographed or recorded - surely it depends on (a) the reason for doing so and (b) the prevailing circumstances.
As far as sessions of traditional music and song are concerned, people record either to learn tunes and songs, or with the intention of trying to relive that session. As long as the recordist is not making him or herself a pain in the arse, I can see no objection to the former. When I was singing, I would have been flattered if the latter were the reason. In a club situation, you always ask. I can say that whenever we recorded at a folk-club, I can never remember having been refused permission.
It is not always possible to get everybody's permission to record during an open session, in which case, a touch of discretion and sensitivity is advisable.
Let's face it, recordings in these circumstances are seldom, if ever publicly usable.
The only objection I can see to photographs is the use of flash, which can be extremely intrusive, with or without permission.
I have to say that if our older traditional singers had adopted a similar prima-dona attitude to being recorded to that which has been displayed here, our repertoires, and our enjoyment and understanding of the tradition would have been very much diminished.
Jim Carroll