I also note that nowadays 70% of photos taken on Flikr seem to concentrate on the male form in what I imagine is a sexual way. I am sure these get put up on
'oneclickpricks' 
or something similar.
I have also noticed that the gay male snappers often concentrate on the clothed/topless females on the ride too, often overlooking the FF riders. This rule comes up in the Solstice rides too.
I think that for many riders (M and F) there
is a latent sexual element, it is a mild turn-on to get fully nude in public, it's exciting, liberating and you are also promoting a worthwhile set of causes at the same time.....I know having done it more than once!