Many do it.
There is a guy on this board that has 10 or more fake google accounts. I don't know if he ever got caught. If I was his competitor I would of flagged his listings and brought it to google's attention.
Google is very aware that companies are doing it and they are giving out spankings.
Google does check up on things. The called me the other month to verify something they saw.
(it wasn't one of those stupid sales calls where they pretend to be from google)