I got a call today, 06/18/2013, from a man in New Jersey stating that he had an "opportunity" for me with a company called "Tyco". Yes, this is a real company (they used to make toys in the 1960s and 70s). It was for a File Clerk position.
When I asked him about his company's physical street address and in which city he was calling from, he became quite flustered, repeating a 'pat' answer about how his "managers and supervisors require the emails to only have my name and company name, Collabera, in the footer of the emails. If you want the address of my company you can go to our website..." and I cut him off.
ALWAYS, ALWAYS, always a company WILL have not only the person's title at the company, and the street address as well as the city, state, and zip code. That was the red flag for me and I thanked him and hung up.