MAG

This one is fairly easy. To do it, just rush to the D point at the beginning of the game, and wait until the point is secured by another faction. Then un-secure it immediately, and try to defend it at all costs. Be careful as many people from other factions have the same idea. As you need to do it only once, you won't need many games to obtain it.

Be careful, you won't obtain the trophy if your faction has the control of the D point. If an enemy unsecures it, and you prevent the unsecuring, this won't count. Thanks to SirkSirk for the tip.