Okay kiddo, have you ever heard of a man named Hasan M. Elahi? He's a really interesting guy who does something called "self-tracking."
You know how sometimes you use GPS on your phone to help you find your way when you're lost? Well, Hasan uses GPS and other kinds of technology to keep track of exactly where he is and what he's doing all the time.
He does this because a long time ago, he was at an airport and some people thought he might be a bad guy. Even though he wasn't, it was a scary experience for him. So he started to keep track of everything he did and everywhere he went, just in case someone ever thought he was doing something bad again.
Now, Hasan even puts all this information on his website for everyone to see! That might seem like something you wouldn't want to do, but he thinks it's important for people to know that he's not doing anything bad. Plus, he wants people to think about privacy and how much of their own information they might be sharing without even realizing it.
So, long story short, Hasan M. Elahi is a guy who uses technology to keep track of everything he does and put it all online for people to see, so they know he's not up to anything bad.