Following Monday's Europol press conference on the global scale of match-fixing, Philly.com's Jonathan Tannenwald asked MLS, the NASL and the USL what they are doing to combat this problem. MLS in particular seems to be taken a very proactive approach to the matter and it's one that started before the Europol news.
In addition to having a "soccer security agent" in Las Vegas to monitor gambling activity (which sounds like a job for the cross between James Bond and Hunter S. Thompson) and hiring a director of security, MLS is also cutting off dressing rooms from the outside world on match days. From the league's statement to Philly.com:
This season we are instituting a ban on phones and electronic communication devices from within the locker room 60 minutes prior to kick until match's end. This includes social media.
Not only is this a way to keep match fixers from communicating with players and anyone else with influence on matches just before and during play, but it could also prevent the vast potential for PR boners from footballers tweeting at inappropriate times. Whether social media and electronic communication during matches is an actual match-fixing concern or not, it's the perfect excuse for any league to ensure that for at least the most important hours, players are focused on their job more than their Instagram accounts.
UPDATE: According to MLS, many clubs within the league already had similar rules on phones/social media. This will apparently just make them more uniform and ensure a league-wide ruling.