alt Hacker NewsHosted services can't really be "free as in freedom". We can't know for sure what software they're actually running and users don't have any freedom in using their service since that is entirely at their pleasure. For something to be free the thing has to be able to move beyond its present controller.
Isn't that the case fro AGPL? You have the control over the source code and can change it, even if the current instance is not in your control.