I was thinking about this now, maybe it’s a stupid question, but anyways… Let’s say that a person takes a picture of a second person, and this second person uses this picture, for example, in a social network as a profile pic. Could the first person have something against it? 
In social networks like Facebook, tagging has always been a common way of sharing photos, right? So in that case, I don’t think that the first person has good enough reason to screw the second person.
In the picture, it’s the second person in it, right?
So although it’s the first person who owns the SD card memory or the film or whatsoever, I think it’ll be okay to for the second person to use it as his/her profile picture. If both persons are friends, that it’ll easy for them to talk about it and ask “consent” from the owner of the picture.
Well that’s, at least, how I see it, in my own point of view. And by the way, I’m not a lawyer.
And I don’t find your question stupid. 
I know this situation often happens.
P.S.
We should also take note, what really is the terms and conditions when we upload photos in social networks, knowing that most of us (as far as I know) are quite aware that these photos can easily be copied, downloaded and etc.
I’m not so sure how to see this in a legal perspective.
In my opinion I would say if you uploaded a photo of a person in which wasn’t your friend or family member then they would have something against it.
I have had my picture taken from FB before because a 14 year old kid got annoyed that I didn’t have time to help him, after about 4 hours of demanding it to be removed I told him what legal rights I had and he took it down.
My understanding is that in most countries, photographers by default will retain the copyright to any photos they take, unless there’s a specific agreement to the contrary. So if the subject of the photo then uses that photo as their profile image, they should in theory seek permission from the photographer first.
Yes, that’s the situation I was thinking about.