Got a call from this number today at 8:33 AM Mountain Time. Caller ID was "I 1-720-452-5626" The call rolled thru to voice mail; but they didn't leave any message. Checked 800notes here for other reports about them, which confirmed what I expected. Added their number to my Call Block List; so any future calls from these guys (whoever they are) will automatically get disconnected.
Caller ID comes up with the single letter I. When I answered it there was silence at first and then some man saying something about federal agent with a badge number. Then he hung up. When I tried to call back I got a recording saying that they were away from their desk or maybe the office was closed. If I wanted more information to leave my phone number. As they already had it, I hung up.