New ask Hacker News story: Ask HN: Why do I get robocalls from recently-called area codes?

Ask HN: Why do I get robocalls from recently-called area codes?
43 by gnicholas | 41 comments on Hacker News.
Over the past few weeks, I've started receiving robocalls from area codes that I happen to have just called or received a call from. At first I thought this was just me noticing a pattern that wasn't really there, but when I looked back at my phone records I could see that I had literally never received a phone call from either of these area codes, and that within a day of talking with someone in that area code I started getting robocalls. Has anyone else experienced this? How would robocallers get this information — interception, buying it from my cell phone company, or something else? Even if they're just buying a list of area codes I've talked to, this seems completely inappropriate. And if they're getting the actual numbers, that's even worse.