Why do I keep getting random calls like this?

On my iPhone I keep getting these random calls. I got them on my other phone too. They're sometimes telemarketers offering tax services. I got another call from a "lawyer in New York" threatening to proceed with the "charges" if I did not call back in the next week. Some of them are calls from actual people. If I try to call one back, a real person answers and it freaks me out. A lot of them have accents, too. All the calls are from major US cities, spread out everywhere. There's no pattern other than that.

What is this? Does this happen to anyone else? Is there some sort of secret network? Am I being stalked?

I live in lebanon and I've received loads of calls from other countries. Most are from the us, but I sometimes get calls from neatherlands. I believe this is happening to locate your location or something. I stopped answering the phone calls and they just stopped. Do the same. Don't answer them. Hope I helped