This is from Call Wiki:
Additional Number Variations: 201/520/9603 - 201.520.9603 - 201 520 9603. The description we have for the 201 area code is: N New Jersey: Jersey City, Hackensack (see split 973, overlay 551). Since 201-520-9603 belongs to the 201 area code, we also know that the local time in UNION CITY, NJ is 15:42pm. The phone number 201-520-9603 is assigned to MCI WORLDCOM COMMUNICATIONS, INC., NJ and the actual exchange location is in UNION CITY, NJ. Technically, the telephone exchange switch is identified as NWRKNJ41DS0. Other phone numbers in the 201 area code that also have comments are 201-176-5056, 201-200-9999, 201-201-2424, 201-204-1294, 201-207-0667, 201-210-3618, 201-210-5381, 201-210-5418, 201-210-5437 and 201-210-5973. The owner of 201-520-9603 can be obtained through a detailed report. As well, the address and number type is also available in a detailed report. CallWiki END
Where else are they getting information about you? From those surveys that claim to reward you a “free” laptop or some other “free” doodad that'll end up costing you more money in the long run because of the crappy quality of the “free” whatever. You don't even have to finish the survey to give these bastards what they want – the teeniest bit of information about you. If you don't want the calls, don't fill out the surveys. It's as simple as that. I keep saying that there're “free lunches” anymore.
So you say that you put your name on the national DO NOT CALL LIST. Well, bully for you! That would take care of about 2% of your harassment calls, if that. These bastards who keep calling, though, don't play by ANY rules except their own. The best thing to do is for YOU to be vigilant about who calls you and make use of your phone company's BLOCKED CALLER LIST. You may complain about it being an extra expense you can't afford. Well, that's up to you. If you don't block them in some way, then you deserve to get those harassing calls. Don't sit back and depend on a national DO NOT CALL LIST to end those calls. If your phone company doesn't offer a BLOCKED CALLER LIST, find one who does. I think it's a small price to pay for not hearing about some new way to separate me from my money or lower my credit score.
If you're one of those people who feels they have to answer every single phone call, train yourself not to. You won't hurt a telemarketer's feelings by not answering, trust me. THESE BASTARDS DON'T HAVE FEELINGS. They don't care if you're a soccer mom hauling around a van load of kids or CEO of your company. They just want your money or information about you and they'll do whatever to get it. Not every phone call is so earth shatteringly important that you have to answer it!
Lastly, my question is why post a message to those bastards here that says, “Stop calling me!”? That does absolutely no good whatsoever. Are you people really THAT naïve to think posting a message to stop calling you is going to end the harassing phone calls? Think about it.