The problem is not that security solutions are a double edged sword, it's that such solutions stop mass surveillance.

When Ross Ulbricht was arrested, they made sure to do it in a way that they got access to his laptop while logged in. I'm sure competent investigators can figure out the login method used daily by someone on their phone if they follow them because they are committing a crime. Just like they did with Ulbricht. But they can't do that for everyone whenever they feel like it, and that's the problem.