Twitter experiencing serious problems

Today my twitter account simply disappeared. I found out when keybase notified me that it had found that my existing proof of twitter account ownership had been deleted. I tried logging in and failed to do so, and when I looked at my public profile it 404'd. This is not an account suspension because that would look like Milo Yiannopoulos's, and it's not a case of a deactivated account because logging in is supposed to automatically reactivate according to twitter's support

It doesn't affect all networks: It seems to be broken in most regions (I've sampled about 12 locations across Europe and the US east coast), but my Linode VPS has no problems, nor does the UMBC VPN. HN user slater reports that it works on his home internet as well.

Bluescrn reports the same issue, and I confirmed that his problem is distributed across the same networks as mine.

Cuonic reported that new account registration is broken, and it seems to be the same on my network.

Tabloids are reporting the Kanye West's twitter account has disappeared as well, and it seems to be the same issue.

This has all the features of a caching malfunction, but this fails to explain the signup errors, and there doesn't seem to be any ISP or geographic pattern to where the problem occurs, based on my limited sampling.

Edit 18:44 EDT: It looks like most (all?) affected accounts, as well as the signup problem, have been resolved. It remains uncertain if all networks are fixed. I am collecting data about the distribution of the problem.