It's NOT OK for a telemarketer to call a wireless device according to the FCC, even if you aren't on the do-no-call registry. You can file a complaint with the FCC under "FCC Form 1088" on this page:
http://www.fcc.gov/cgb/complaints.html
what is up with this? i have been getting so many unknown calls lately. i just got one today from the same number 650-720-9075. i usually don't answer, and i never call back until after i have googled the number to make sure its not bs. but as it turns out, it is bs. WTF!
They called me today as well on the cell. I contacted AT&T and despite usually being really non-challant about customer service, they took the number down and said they will go after them.
I guess if enough people will report this number to the wireless providers, they eventually will be shut down.