They call 3-7 times in a row at 4 in the morning. They sometimes call during the day (like now: 3:50pm). They never leave any messages. My friend once did pick up and it was a male individual who asked for someone, but he was hard to understand. He spoke with a thick accent, seemed like an Asian accent. This has been going on for the past month or so. Extremely irritating, especially when he calls in the middle of night and wakes me up. He also uses 443-552-5001. I don't know of any of the other numbers but they are usually 443-552-500(some digit).