When Krall attacked Yorktown, he had a pretty easy time of it considering he lost about 98% of his forces to "Sabotage." He managed to penetrate the gates with only three ships and even got all the way to the ventilation system without much trouble. Even the USS Franklin was able to break through and fly all around the starbase before crashing into one of the artificial rivers.
So where was Yorktown's security during all of this? For such a major station, you'd think they'd have more precautions for events like this. Or, at the very least, better first responders. Even after the Franklin made its water landing, we didn't see many security vehicles, or even Federation crafts, show up to the party. Greg Grunberg's Commander Finnegan has a lot of beefing up to do if he wants to keep the starbase safe from would-be terrorists.
