If they are calling at 1 *AM* then they should be REPORTED to both the DNC *and* the FTC. This is a violation on MULTIPLE levels. You could also try your local law enforcement, although they are likely to blow it off.
I have just received the 9th call today from this number (781-241-4613) and caller name (Cambridge MA). I am going to block this caller with the call blocker included in my Panasonic cordless telephone.