That's a lesson many here could stand to learn, to be honest. With all the private stuff that gets posted sometimes, I occasionally wonder if people realize everything they write here gets broadcast to the front page of the forum. You're making yourself vulnerable to data scrapers.
It's complicated, but essentially there are people on the internet who go around collecting personal data. Sometimes it is done for exploitative reasons, sometimes it's just done for mockery. Often there will be no direct repercussions for you that you are aware of. But it is usually always a good idea to be careful how much of yourself you put into a public space, because you never know who is reading it, and what they are doing with your information. If you have something to say that's private or personal, it might be better to put it in a private message and thus control who gets to read it.