[upofadown]

Active attacks that are really trivial to perform in the case of something with a single server controlled by a single entity. Most of these things take that form.

>Having to verify safety numbers out-of-band is an inescapable physical truth...

The reasons for this are fairly opaque to most people. It is kind of dishonest to just assume that people will do the checks for no real reason. You have to at least allow the user to understand the tool.

Note that Signal made it easier to ignore the change of a safety number a few years back. So in a sense they are getting worse at addressing the problem.