Interesting topic. : D
For me, I have spent a lot of time in various online communities. This is probably the most trusting and open-hearted one, in my experience. That's probably why it's so annoying when someone seems to betray our confidence and play us.
I have seen a lot of spam (not so much here, but in general) that is commercial-based. Of course it's annoying, too, I just consider it part of the whole package. And also, at least I can understand the motivation for it.
But I simply don't get people like the dominatrix marine biologist (sorry, but I had to say it What is going on in their heads? What is she (or very possibly, he) wanting from this forum? Is she finding it amusing to upload weird pics? Etc etc yada yada.
And "Kelsi." She wasted the time of people who took her seriously.
By the way, I want to alert you all to a very simple tool for locating images on the net. It very quickly helped me find an image of "Laura" that was really stolen from a fashion blog. (Also "Kelsi" seems to have taken a pic from a woman on Facebook--I sent that person a private message to let her know.)
https://images.google.com/
It's good for anytime you want to ID an image, obviously.