When once the NSA was able to recruit the best and the brightest, now they are going on to work for much higher salaries in the Silicon Valley. In the short term, law enforcement will be outpaced by technology. Technology is changing faster than they can keep up with it, much less get ahead of it. In the long term, there is going to be an ever narrowing line between protecting the citizenry and violating their right to privacy. History has shown that these agencies have not followed the letter of the law, so to say that legislation will solve the future problems is naive.
Several possibilities exist.
For an Orwellian 1984 future to take place is not out of the question. Governments have already asked for all encryption keys in an attempt to keep up with technology. Though the infrastructure is not in place to literally view every message and keep a file on the activities and communications on every citizen, the possibility exists. Hysteria, panic, and fear of terrorists violating our national security may cause the average citizen to allow the government unheard of power for surveillance. To take a more hopeful approach, one can foresee a time when the FBI and NSA is able to target specifically the communications that directly threaten our national security and bypass a very high percentage of those that are not.