Source: I work for a company that handles online rebates and promotions, including these types of Twitter/Instagram/FB contests. We deal with the FTC all the time.
He had a several radios and 2-3 phones and just madly speed-dialed into the station when each round was announced. He even had to disguise his voice because he won so often that the stations tried to avoid him winning.
I can't find the story but here is somebody similar:
http://www.dailymail.co.uk/femail/article-2809341/Woman-addi...
I've found that I sometimes don't even receive the prize, and occasionally don't even know what the prize or radio station are when I'm calling in as it's reflexive at this point.
"The defendants’ letters led many consumers to believe that they had to pay a processing fee to receive the cash prize"
It's funny that this came up. Just the other day I heard them running a "text us to win" contest on the radio while driving and I thought I should create an app that enables find-and-share capabilities for text-to-win contests.