[DannyBee]

IP lawyer here :)

"If so, why can't an author make this part of the license?"

So let's separate out two questions implicit here:

Can you make this part of a license?

Would you win if you sued someone for violating it?

The answer to the first is clearly yes, you can license it however you want :-).

However, like most IP, in basically all countries there are limitations on how you are allowed to license things, to ensure the original goals of copyright are respected.

Those limitations are usually presented as defenses.

Van gave two examples of defenses.

There are others.

For example, patent misuse is a defense to patent infringement.

Here's a concrete example of patent misuse that may be easier to understand than copyright misuse:

You sell a thing that infringes my patent.

In order for you to avoid infringing my patent, I force you to pay royalties for 10 years (Rather than a smaller length of time).

But wait, the patent expires in 5 years!

Can I enforce this?

No. It's patent misuse. You cannot use your currently valid patent to force someone to pay royalties past the validity period of your patent.

Another example:

You have a product X that infringes my patent. I use my patent on X force you into an agreement to pay royalties on a product Y that doesn't infringe my patent.

Can i enforce this?

No. You shouldn't be able to use the patent on X to force me to pay royalties on something that doesn't use your patent.

To bring it back to Van's examples, the copyright misuse is similar to the patent misuse i just gave you.

You can't leverage your copyright on X to force me to do something with an unrelated thing.

The GPL and AGPL are very careful about this. The AGPL applies to modified versions (which are derivative works) and only extends to pieces that are derivative works. The GPL is the same - only the derivative works are touched. That is within the copyright rights of the thing that was AGPL/GPL'd.

How do you know it's unrelated to a given copyright?

If X could not claim any copyright rights over it, it's unrelated. This usually comes down to whether it's a derivative work not because the other rights are not very broad in coverage.

Here, the license is taking X, and saying "You must do something with unrelated thing Y, which is clearly not within the scope of copyright of X". So I am trying to use my copyright right in X to force you to do it. Note: No lawyer believes there is any reasonable argument that completely and totally independent piece of software X that does say, monitoring, is a derivative work.

So that's a good start on copyright misuse :)

(The other prong is about whether it restricts competition, which they already admit is their goal here)

[ninkendo]

I have a question about how derivative works are defined with respect to AGPL.

With the GPL, you couldn't distribute software that links (at runtime) to GPL software, without open-sourcing your software as well. This is because, linking another piece of software to a GPL'd binary means you're creating a "derived work". That's why they made the LGPL (the "lesser" public license) which allows being linked to from closed-source works, without being considered a derived work.

With AGPL, they seem to have gone the opposite way from LGPL: it seems to have extended the definition of "derived work" to include software that accesses the covered software over the network. If that's the case, doesn't that mean you just plain can't use MongoDB in the backend your own closed-source website (without open-sourcing your site's code?)

[nebulous1]

I think you're slightly off there. The AGPL doesn't apply to software accessing the AGPL licenced software over a network, it applies to the AGPL software that's being accessed. As in it applies when the software is being accessed over the network rather than when it's being distributed (as with the GPL). This is actually mentioned in the article.

[vishvananda]

I think you have this correct, as I understand it. Just to explicitly state the differences:

1. You can modify GPL code as much as you want, and as long as you don't distribute the software, you do not need to make the modifications available. If you distribute the software, you are required to make your code available.

2. The AGPL extends the definition of distributing the software to making the software available over the network. This means if you modify AGPL software and then make it available over the network (as SaaS, for example), then you are required to make your code available.

[ninkendo]

> The AGPL extends the definition of distributing the software to making the software available over the network

Doesn't this apply transitively? That is, I made MongoDB available over the network to my web tier (thus creating a derived work), and made my web tier available over the network to your browser (thus distributing it), thus, haven't I transitively made a derived work from MongoDB available?

I ask because this exact scenario seems to be what makes the company I work for so scared of AGPL. It's not necessarily cut and dry, but it's a scary enough possibility that we just ban it outright.

[greenshackle2]

Runtime linking doesn't always equals derivative work. Some GPL enthusiasts would like it to be that way but it doesn't mean it is. As far as I know it's a murky legal issue. I forget the exact case but one counter-example was: you have proprietary library A. Someone makes a GPL implementation B with a compatible interface. You ship software C with instructions that users can use either library A or B. An example of this would be BLAS libraries, which have both proprietary and open-source versions. Software C is obviously not a derivative work of GPL library B.

Now, the risk that a court might decide your software is a GPL derivative because it links GPL software might be enough to dissuade your company from using GPL software altogether.

LGPL makes it explicit that you can link against the software without making your software GPL/LGPL so it removes that risk.

And that's not what the AGPL is about. It's not extending the definition of what a derived work is, that is completely outside the hands of the license, it's a matter of copyright law. The GPL says if you distribute GPL (and by extension GPL-derived software) you must distribute the sources too. The AGPL says if a user accesses AGPL (and by extension AGPL-derived software) over the network, you must distribute the sources to that user. It doesn't mean that if a user uses unrelated software to access AGPL software, that unrelated software is somehow derived from the AGPL software.

[int_19h]

> I forget the exact case but one counter-example was: you have proprietary library A. Someone makes a GPL implementation B with a compatible interface. You ship software C with instructions that users can use either library A or B.

Are you referring to the discussion between the author of CLisp and Stallman about GNU Readline, by chance?

https://github.com/JoshCheek/clisp/blob/master/doc/Why-CLISP...

[thawkins]

Also the only part of mongo that is limked is the driver, not tbe database product. All the drivers are licened under apache 2 license, which is permissive, and largly just demands preservation of copyrigths and trademarks. It does not mandate source distribution for derived (linked) products.

[nebulous1]

Let's hypothetically say that a court agrees that this is copyright misuse.

Where would that put existing MongoDB released under the SSPL? Surely not public domain, so where?

[DannyBee]

Depends on how well written/what court decides to do.

I'm going to short circuit a lot of nuanced case law and differences between jurisdictions/courts here to give a clear answer:

Usually these things are written so the clauses are severable.

The court would then most of the time just remove the invalid pieces and leave the rest intact.

If it is not severable, the contract stands or falls as a whole.

If it falls, nobody is a valid user (though surely would be given time to stop or for mongo to fix it).

Why?

The default state of copyright is that only the owner has the rights.

If you invalidate the contract/license granting you non-exclusive permission to those rights, you no longer have that permission at all. So you have no right to be using it.

note: Any such court decision would only apply to the relevant court jurisdiction (IE if it was a district court decision, it would only apply to the parties)

It would just be persuasive evidence to other courts.

[VanL]

Interesting thing about misuse, is that it prevents the enforcement of the copyright against even non-parties until the misuse has been dealt with.

Practically, that is probably dealt with via a blog post and a retreat to the AGPL, but still.

[DannyBee]

"Interesting thing about misuse, is that it prevents the enforcement of the copyright against even non-parties until the misuse has been dealt with."

Interesting. I've never delved that far into misuse but that makes sense. Is that piece a US specific thing or common in others?

As you say it would not have too much practical effect since it's curable trivially. You'd get a few hours of unrestricted mongo use, maybe, but I bet the official order would post-date the blog post fixing it :)

[VanL]

Probably US only, didn't look internationally.