The Metal Gear Online PC beta that kicked off yesterday has already been suspended because of a possible exploit that, according to Kotaku, allowed players to acquire MB coins, the in-game currency that's normally purchased with real money, without paying for it.
Konami itself has said nothing about the nature of the exploit in the suspension announcement, nor when the beta will be restored. Due to a possible exploit, we've removed access to the Beta temporarily while a hotfix is being prepared, it states. Once the issue is addressed we'll provide access to the Beta once again.
Metal Gear Online has been live for consoles for a few months now, but different platforms, different problems, as they say—and getting these wrinkles ironed out is what a beta is for, after all. We'll keep an eye on things and let you know when Metal Gear Online is actually online.