An 'ulterior motive' to photograph?

This email comes from a pre-school professional, about the difficulties of taking photos of kids:

'The problems you highlight all relate back to: guilty till proven innocent. This threat hangs over teaching staff all the time - especially male staff like myself. I recall a time when I was taking photographs of various activities at our pre-school when a parent jested "Likes his photos - probably got an ulterior motive." This was deeply unfunny but it forced me to think again. I now leave most of the photography to the female members of staff. Unfortunately they have no idea how to compose a decent picture but rather that than a sudden police raid!'