Can someone tell me this person's information?

[Harshit]

you can,t get their names but yeah you can get the location from which they have associated their sim.
please mention in comment that from which country you are because mobile locator services like http://site1.way2sms.com/jsp/LocateMobile.jsp generally depend on countries....... mail me your country at updatebaba@gmail.com so that i can help your further...
moreover if you are really getting irritated then go to police and ask for surveillance service ...by using servillaence you can also get their live locations and even the numbers but for that you have to file report againist them