This number on my call display was prefixed with L1. I think that may be a country code? The came at 10:22pm on a Monday night and no one replied when said hello. I could hear the line was open and someone was listening. I stopped speaking and after a minute or less of waiting, they hung up. When I called the number back, it said the number was out of service.

Getting calls from here at night 10:45 tonight, this is crazy!!!!

EXACTLY the same comments as  "Annoyed at this late hour" wrote, plus the number above the phone number prefaced with an L1 on my call display was the same phone number (without L1) prefaced with 44. I think the 44 is actually the country code. I get calls anytime between 6pm thru 11pm at night, always with someone listening on the other end then hanging up after silence and listening to me talk. How is it possible to find out who the caller is when the number is not in service?

My Calls Have Been coming early morning & REALLY early 6:05 am 1:05 am But Most have Been 3:am Right In The Middle Of Rem Sleep

Go here for a detailed discussion on call blocking devices:
http://800notes.com/forum/ta-5d4e343675a5629/call-blocking-devices