This is such crap. I would like to know about this number

Just got a call from this number and they didnt leave a message.When I called back busy signal......

I missed a call from this numberon my cell, called back and it was a busy signal. what the hell?? Does anyone know who this is callin?

i rec'd a call from (305) 840-5321 on my google-voicemail acct; this appears to be some sort of computerized bot dialing numbers ... as long as no voicemail is recorded, then it's not in violation of any restrictions; it's just the hacker's way of double-checking what's a voice-line versus a data-line.