They called once row today. I did not answer and they did not leave any voice message. As I am in a job search, these annoying calls must be likely from career advisor or back to university places but not from any serious work offer. As far as I know, it is illegal to collect phone numbers to use them for any different purpose as these guys are doing.
Please be careful. A guy said I had applied for a job and he was from an agency called Career Advisor. He wanted to see if I was a good fit and he had a few questions. I said "What was the job I applied for?" and he immediately hung up. Very fishy, please beware if you get a call from this number and don't give out any info.