[MaulingMonkey]

Square is bound by copyright law just as much as anyone else. Agreeing to that license is the only thing giving them permission to redistribute it in the first place.

This is why we have the DMCA safe harbor provisions - it'd be incredibly easy to be on the hook for copyright infringement as a company hosting any user content otherwise. Those safe harbor provisions aren't a blank check to knowingly commit wanton copyright infringement however, as can be seen with all the legal wrangling over Megaupload, as an example [1].

Square knows about the AGPL, knows they might not be abiding by it's terms if they redistribute AGPL code, and knows they probably don't have the right to redistribute under any other term. They can choose to knowingly possibly violate the license, or to knowingly commit copyright infringement, or to ban AGPL code. Those first two options, with that "knowingly" in there, open them up to potential legal action.

> And AGPL isn't the only "must publish all your server's source code" license available, so to prohibition is too specific if that's the actual reason.

If you make Square's lawyers aware of some of those other licenses, it wouldn't suprise me if they get banned too for the same reason. It's not like they have psychic knowledge of the existence of all licenses. Failure to audit the universe doesn't mean that's not their reason.

[1] https://en.wikipedia.org/wiki/Megaupload#Safe_harbor_provisi...

[eesmith]

Square didn't agreeing to that license. A third party did.

If the third party sold a copy of MS Windows using Square's services/software/platform, could Square even in theory be sued by Microsoft for copyright infringement?

It sounds like "yes" from my reading of what you write. So AGPL isn't something special.

Their lawyers don't need to be psychic about other licenses. Why did they specifically qualify with "v3"? That is, the original Affero license is one of the other alternatives, yet they seem to allow it.

[MaulingMonkey]

> If the third party sold a copy of MS Windows using Square's services/software/platform, could Square even in theory be sued by Microsoft for copyright infringement?

If Square was knowingly engaged in the distribution of Microsoft's software against Microsoft's license terms, absolutely. (EDIT: Well, I'm assuming they're helping distribute it, might be "conspiracy to commit copyright infringement" otherwise?)

> So AGPL isn't something special.

Correct...ish. I'm sure piracy, if not explicitly against the ToS, will get you kicked off too. The closest the AGPL gets to being special is the nebulous situation we find debated throughout this HN discussion tree - is it legal for Square to distribute? It's reasonable that customers might think so. It's reasonable that square's lawyers might think not.

But you've pointed out that even that isn't unique to the AGPLv3 specifically - so why call it out, specifically? My wild uneducated guess - a customer used AGPLv3 software, Square became aware of it somehow (license review team? or perhaps someone tried to exercise AGPLv3 rights and requested server code?), and eventually involves their Lawyer. Lawyer then looks into the specific case of their customer using specific software, reads the license of said software (AGPLv3), and becomes nervous about Square's possible legal exposure.

After the awkward conversation with their customer (possibly much like the discussion in this HN thread as to if Square would/wouldn't be knowingly facilitating AGPLv3 license violations by not sharing their own code, and thus legally liable), Square settles the matter by banning the specific license outright, possibly after giving them a chance to move away from AGPLv3 software first since it wasn't strictly against the ToS, and then explicitly adds it to the ban list for the benifit of customers and customer service who probably weren't privy to whatever lengthy private discussions might've been had with that one specific customer.

[eesmith]

I like your guess.