I totally disagree that this came off sounding like a plug for Tarsnap. This is one of those perspective-changing point which can only be made by using concrete examples.

That he happens to be an expert in the field of digital privacy and has a way to prove that he is such an expert shouldn't be held against him.

Reading his post was like an "oh shit, he's right" moment for me and using Tarsnap as an example was key in helping me understand it.