"Wherever it is done"? Do you know the laws of every country?
I come from one where it is legal to film and photograph in every "public space" that is not the interior of a courthouse or police station etc. In swimming pools and gyms (mostly owned by the state or municipality) you have the right to film and shoot just as much as in the street. People often find it rude and ask not to film them, but that is another matter. High school kids and other groups often pose for eachother's pics, while others are around.
Go to the yahoo groups of Eric Deman: start with
http://groups.yahoo.com/group/e_demans_male_sports and enjoy! This man once went into the shower rooms of triathletes around here and just asked 'can we film?' They all indifferently mumbled, 'yeah, whatever, dude'. Since then he's done it more often. He even sent emails to 200 amateur football clubs asking if they wanted to strip and play in their own showers 'for a gay website that shows straight sportsmen' and some 40 teams said yes! The trick was to add an element of competition: the team that put on the hottes show was going to win VIP tickets to a big gay disco for each player and his wife/girlfriend.