It's a license that requires any changes you make to the code be made available to the public as well as all code that connects to it in related services.
It is a license that touts "ultimate freedom" but the reality is that it removes your freedom to make changes that you would like to keep private.
I don't believe that's a correct interpretation of the AGPL. It's intent is to extend the idea of "User right to run" the software to services (like eg a web server or a web app) -- in other words -- say you make a webmail system, release it under the AGPL. Users of your webmail system would then be entitled to the source, just as users of a GPLed mail program would be entitled to the source (under the GPL).
The basic idea is to avoid someone taking something like a web server, heavily build on it, and set up a big service running it -- but not providing the modifications back to the users of the service (and eg: leaving them "out in the cold" if the service shuts down). Or in this case -- if you fork pinry, that's fine -- but your users are entitled to the source and your modifications (note your users not everyone).
I think it's a perfectly valid licence, and appropriate for stuff like this, where you could take pinry, set it up as a service, slap some ads on it, and make money off of the value created by pinry's authors. Nothing wrong with that. But if you find and fix bugs, those fixes have to be contributed back to at least your users (which then again are free to redistribute them under the AGPL, making it likely that they find their way back to the original project).
No it doesn't. It gives the right to any users of your service to get a copy of the source code under the same license. Has nothing to do with "code be made available to the public".
Does AGPL have any notion of boundary between AGPL and non-AGPL software components? Something like a lesser/library GPL seems more fair: the 'LAGPL' components people use is open sourced to them, so the I/O network flaw of the [L]GPL is fixed, but the other parts of the product have their own license.
A regular GPL with a constraint on number-of-users seems fine for protecting the openness of a product intended for personal (non-hosting-provider) use, and pinry can license a commercial version for hosting providers.
It is a license that touts "ultimate freedom" but the reality is that it removes your freedom to make changes that you would like to keep private.