Why are sites like Yahoo, Facebook, and Google/youtube suddenly showing personal information publicly?

Facebook would show my location on pages a few months back, so I had to manually fix it which took about an hour or too and didn't even show it was fixed at first. Then, Youtube changed it so that unless you know EXACTLY what to click on while creating an account, it will show your real name (First and Last) as your username to everyone. Now, Yahoo is showing locations when you comment and only stops if you check a certain box every single dam time. Why are the most popular sites out there just allowing information to show like this?

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note: by information showing publicly I mean showing things to everyone that's not your "friend". Anyone in the world could see where you live (city, state/province, and country) and in Youtube's case, your FULL NAME. This makes the internet even more dangerous for both adults and children because this information can easily be used to track people. Of course, the sites that do this call it a "feature" and would "make things more interesting." The only thing they do is pose a threat to most users, ESPECIALLY those under the age of 18. This is a big deal, and is a very dangerous thing for these companies to do.