How would you feel if you walked by a porn shop, and in the window you saw a magazine cover with a photo of you taken from your public social media accounts printed on the cover with the headline, "Hottest people on Instagram to get off to in 2021". Some people may be flattered by that, but many, many people would feel that it was a violation and an assault to their dignity.
If you look at this hypothetical case without prejudice, the only difference with your photo appearing on a news site, in someone's post on social media, as a picture on some forum or just being uploaded to image sharing service is for-profit nature of the usage.
No. Even nonprofits (see Wikipedia) have to follow strict rules about licensing images or face legal consequences. They also do a good job of policing this on-upload, something that a site like Wikifeed does not.
Exactly, this is what I'm talking about! To be clear, I'm not saying the case in question is fine. If you condemn usage of your image in porn magazines, you should condemn it in other situations as well, as long as the for-profit nature of the usage is not the only thing that bothers you.
On the other hand, copying a picture to another website can also be a copyright infringement.