Comment by cookiecaper

Snowden had the element of surprise. They weren't actively trying to monitor his comms because they didn't know he was a risk until after the leaks. If the state wants to decrypt your messages badly enough, they have resources that they can devote to that (as well as multiple side channels that are probably easier than forcibly decrypting, including the infamous "beat with a wrench" trick). It's not trivial to defeat strong encryption, but it is doable given sufficient interest.