If there were such methods, and if these methods were used to compromise-proof an institution, then that institution would see the hammer drop down on them from above like nothing anyone (bystanders, pundits, the world) has ever seen before. Everyone scooped up with black headbags on, rendered to black ops sites.
Because, at that point, the government has exactly one play left... to make everyone so afraid of compromise-proofing that no one bothers. This isn't unprecedented, by the way. Silk Road and Dread Pirate Roberts was a similar situation, and they used illegal NSA surveillance to unmask him and parallel construction (https://en.wikipedia.org/wiki/Parallel_construction) to prosecute.
When they have a monopoly on violence and trillion dollar budgets, you're going to lose even if you have superior tactics.
Because, at that point, the government has exactly one play left... to make everyone so afraid of compromise-proofing that no one bothers. This isn't unprecedented, by the way. Silk Road and Dread Pirate Roberts was a similar situation, and they used illegal NSA surveillance to unmask him and parallel construction (https://en.wikipedia.org/wiki/Parallel_construction) to prosecute.
When they have a monopoly on violence and trillion dollar budgets, you're going to lose even if you have superior tactics.