Reverse image searches are old hat. Been around for years and is something that is often used to find copyright breaches. It's not the only tools online that can used. Think PI and how folk are hunted down and what tools are at hand, especially if one is prepared to pay for services. Then there are the tools the big boys have at hand along with supercomputers
The Internet world is like the wild west and it works both ways. For how much good there is out there, there is just as much bad and security and privacy is something that is often abused or over looked on both ends of the spectrum. It's like a game of cops and robbers...a one-upmanship game that can never be won on either side Something comes out and then something comes out to counter act it.
Social engineering and human psychology plays a big part in this. Just look how easily one puts their trust in someone that wears a fluorescent vest as they appear to be someone of authority or someone wearing a suit is often stereotyped into a certain category. Why do you think people wear uniforms, in the same way that someone wearing Muslim clothing can be seen as a terrorist. Brainwashed by society and the nature of human psychology. As the old saying goes.....never judge a book by it's cover and that is exactly what places like facebook and forums can be used for. Hunting grounds for seeking a target, finding their vulnerability, gaining their trust and then move on in for the kill.
Thanks for posting. Tread carefully folk especially where money is concerned.