The rise of copyright trolls

At a former employer, we had a serious lawyer say exactly that. Of course, what had to be present at http://blah/ was more than just the licence text - we also had to provide full GPL sources for all the software we shipped, and detailed build instructions to enable you to rebuild and replace any GPL software on the devices we shipped with your own build.

Indeed, our lawyer actually suggested that we could go further - we already put a sticker on the device with MAC address and serial number - we could simply put "Software licence details at http://blah/ - you have rights" on that sticker, and as long as http://blah was correctly set up to cover the licence requirements, they'd defend us pro-bono. We also ran this past the FSFE, who verified our instructions on the web site, and then were willing to write a letter telling us that in their opinion, we were compliant given the sticker or the slip of paper. Further, there was no issue with the idea that to get support from us, you had to restore our original software, or with us shipping "surplus" source (e.g. we used gdb internally for debugging - we didn't install gdb on shipped devices, but we could still choose to offer you gdb source code).

This did lead to some challenges for us (we had to come up with a process to let you rebuild things that we shipped outside our infra, to let you reinstall binaries on the product in such a way that it was tamper-evident for our support team, and to reset back to a clean state), but we made it work.