Adam Pearlman may be his real name.
At least it's one of a number of aliases he uses (the others all being ME-sounding), which Pete Williams on msnbc just read out.
Sounds Jewish. Perhaps Jewish conversions to Islam are rare, but not unkown? Question mark because I don't know, but I had the uncomfortable feeling that Nik Berg might have been in the process of converting to Islam. Every society has its share of sympathizers with that society's enemies.