A week ago, one of the sites we were hosting was reported to us by the Russian authorities (specifically, the Federal Service for Supervision in the Sphere of Telecom, Information Technologies and Mass Communications [ROSKOMNADZOR]) for hosting illegal content. They said that we must take it down, or risk having the associated IP address blocked in Russia.
In the current political climate, it's very important to note that the site in question was offering services that are illegal not just in Russia, but in the UK, the United States, and almost every other country we can think of. Our terms and conditions do not allow sites engaging in "any activities that are illegal". We were glad to have it brought to our attention on that basis. If the situation had been different, and (say) we'd been told to take down a website expressing political views by the government of a country hostile to those views, our response would have been very different.
But in this case, the situation was clear-cut. We took the site down, notified its owner that we'd done so and explained why, and responded to the original notification saying that we had done this.
Last night, we discovered that the site had been re-created, and we took it down again and blocked all access for the user. But it seems that this was too late; today a different Russian customer contacted us and said that they could not access their own site, or PythonAnywhere. Further investigation determined that the IP address in question had indeed been blocked by the Russian government. It's accessible from everywhere else in the world -- but not from Russia. This is a problem, because the address in question serves our own site, and a large portion of our customers'. And we have a lot of customers in Russia!
We do have the capability to move sites from IP address to IP address (that's part of why we strongly recommend that customers with custom domains use CNAMEs instead of A records to set up their websites), but this was not designed to be done under emergency circumstances, so it takes time. We felt that in this case, a rapid response was required.
As such, we've implemented a secondary IP address that will work for any PythonAnywhere-hosted website. Over the course of this weekend, we will be testing it. If it is essential that your website be visible in Russia, please contact us on email@example.com and we can move you across during this testing period. If it all looks good early next week, we'll move all other sites on the old IP address over, including our own.
[update] As of 17:15 on 2017-03-07, we've migrated all websites over to the new, unblocked IP address. The only sites that should still be affected are those configured via A records (or similar) to route directly to the old address (a small number). We'll be scanning the sites we host and emailing the affected customers tomorrow.