Our websites were unavailable in Europe starting from 14:00 CET (13:00 UTC, 08:00 EST) for about an hour. There's nothing that we could do on our side to prevent it, as it is related to our ISP. We did not know of any planned maintenance, nor did we know for how long would it last or when it get back to normal, or what is affected.
We got NodePing reports from Netherlands and Romania about sites being down, but most of developers from Serbia, Poland, Ukraine and UK confirmed that they can't access any of our resources (at our ISP). Traffic from other countries (outside of Europe) didn't expirience any issues, to the best of our knowledge. Based on that we've conclude that only Europe traffic was affected.
So far, it looks like it's stabilized and everything is accessible everywhere.