Suppose I wrote a Java library and published it under AGPL.
Now I suspect that company A uses it for server side processing in their internet services. If my understanding of AGPL is correct, this would allow any users of the internet services to request the source code.
Company A says they do not use my library. If this were a "classical" software where binaries are distributed, I could probably decompile it and find some evidence whether this is correct or not. But for server side use on the internet, there is no way to find out (unless they do something stupid like leaking stack traces to the user).
So do I have any means for enforcing the AGPL in such a case?