Amazon AWS EU-West1
We run some monitoring software on a VM instance in Amazon's EU-West cloud, which we use to keep a check on our servers which are in various datacentres around the UK. Yesterday at about 14:00 GMT we started getting buried in alert emails, as the AWS instance couldn't see any of our stuff in Union Solutions, 6Degrees, Node4 and various other providers. We ended up turning the monitoring off, and weren't able to start it again until past 19:00 GMT last night, and it's still a bit flaky today.