How was exposing PRISM worse? I'll admit to being biased in his favor, and somewhat ignorant of what exactly was disclosed and how it could help the enemy, so

How was exposing PRISM worse? I'll admit to being biased in his favor, and somewhat ignorant of what exactly was disclosed and how it could help the enemy, so I welcome some input on that. My starting position is that I don't see how knowing that, say, Yahoo is tapped, has changed the bad guys' day-to-day operations to the degree that you could reasonably say Snowden significantly aided them. Or even if it did, it falls under the category of 'merely' "alerting them of our intelligence capabilities" which we both agree was a "line Snowden crossed." Anyway, however damaging it was, my point is that some slides with a bunch of code names, "data-sharing partners", hints at legal justifications and the bureaucracy set up to carry this out, and maybe some high-level descriptions of how the systems work, is a lot different than releasing the actual code that does it, private keys to the servers involved, etc. It's not like graph theory and data mining are elite subjects only NSA knows, so some high-level descriptions aren't going to help the bad guys much. Handing over complete source code would.