I have a used number. So I do get the occasional calls asking for someone I don't know, for contests I didn't enter, ect from all over the country. However this most recent one is weird. I got a call from this number: (740) 250-2524 and just missed it. When I called back out of curiosity I got dial up sounds thrown back at me.
I tether with my phone a lot through it's diagnosis system over a USB cable. Computer picks it up as a dial-up modem and all is well.
If I was tethered at the time would it have been dangerous and should I be worried? The number returned no results for me.
This might not be the right section for this but I didn't see anything else that fit better.