How will I know if I'm being (secretly) recordered?

I been hearing a lot about hidden cameras in bathroom stalls and changing rooms lately. News outlets made it seem like those incidents were only prominent in other countries, but there was a similar situation in my town recently. I've also heard about people who try to take sexual pictures of people (mainly women) who are doing their own thing in public. Yet, they don't know they're being pictured nor have they given them consent to the photographs.

How will I know if this is happening to me? Is there something I should look for in bathroom stalls and changing rooms? I would presume with the photo situation that there's not much I could do, seeing as though the photo takers seem to do it when the person isn't aware of their surroundings. Has anyone been in a situation like these, how did you react?

/r/AskWomen Thread