Lots. You'd be shocked. Most people have no idea how many enemies we face, how hard others work to protect us from those enemies, and how much goes on behind the scenes so that ordinary folks can live their daily lives without fear.
I was in the military branch of NSA. Every single day there was information that was critical towards figuring out what was going to happen in the future. Every week there was a potential crisis that was only averted by having enough information. And that goes both ways, interestingly. For example, Warsaw Pact generals have said that if they had not known via spying, that NATO had zero offensive plans against them, then the Fall of the Berlin Wall would not have happened.
Listen up. Seventy years later, most people now know that a primary factor in winning WW-II was the higher than top secret work of electronic intercepters and code breakers. Without them, the war would've lasted years longer, and likely ended up with Germany having time to develop the Bomb along with intercontinental delivery methods, and that would've been A Really Bad Thing.
Strong encryption does not make us safer. It makes the job of those trying to protect us and keep us free to do what we want, much more difficult. Perhaps even impossible.
Normally I agree with Franklin that those who give up some essential freedom in return for security, deserve neither. But this is not such a case. It's a valid warrant and need, and there some way should be found to work it out.
Frankly, I'm okay with NSA getting that kind of power, but not the FBI. The FBI has a long history of actively misusing information on various internal groups. NSA has a long history of using information only to protect the country from outsiders. Yes, sometimes they want to collect lots of extra info to sift though, but NSA personnel are overwhelmingly freedom loving people and don't care what people are doing in their personal lives. It's not what their purpose is. They're not directed internally.
Perhaps we need a new organization, one that is overseen by both intelligence and civilian personnel, with strict rules known to all employees, Congressional oversight and court approvals per device intrusion request. Oh wait, that's what NSA already is.