1- facebook ads and ads in general are no longer a good to earn billions of dollars, thanks to adblockers and educated users who just ignore them, last year gmc stopped a 10 mil $ facebook ad campaign, it wasn't working, Big dogs are thinking twice about advertising on the web. And yes facebook sells your information to both governments and marketing companies. a quick search and you'll find thousands of results, in fact mark had many issues with the law, but billionaires don't go to jail you know. And don't forget to check
project RIOT.
2- if i do a man in the middle attack i can packet sniffer and collect passwords, personally identifiable information, credit card numbers from the traffic. I can do whatever i want.
Or man in the browser attack, injecting keyloggers and rats to the sites that the user usually use, i could easily trick him to download whatever i want him to download, since i can manipulate the websites that he visits. I could make the website download the trojan on his pc when clicks on the link, my friends did that years ago to me as a prank :) they told me to go to example.com and when i clicked on the link, adult stuff got downloaded to my pc :) i had to restore windows. but imagine if it wasn't. Hacking is 70% tricking your victim to do what you want him to do. My friends hacked many paypals but I'm not so bad.
i hate hurting people, but we were just a bunch of teenagers. If you want i can do a tutorial on it when i'm done with my final exam though i'm not into hacking anymore.