The text message I got is "Hi, I'm Jill. Based on your resume you match a position I'm filling. If you register at jobnab.com we can discuss the details if you're interested." It appears that jobnab is a headhunting service. I've registered with Monster, SnagAJob, Indeed, and CareerBuilder and applied to numerous companies through their application interface programs (Taleo and others). Yes, I've been applying to many jobs and there's no telling which site they got my info from. When I tried to do the reverse phone lookup, it seems the cell phone is registered on the north side of Chicago.
Got text. No caller ID but message was pretty clear. Said that if I was still interested in finding a job to visit their website. Prolly got my resume online or something.
Cell phones are different than other phones. They want to limit the amount of data sent to keep costs down so they don't send caller ID info. The number has to be in your address book to come up in caller ID.