Don’t panic, keep your shoes on - Google Drive is down. This is a real-deal downtime confirmed by Google and it appears to have begun taking hold within the last couple of hours. Some time between 8:30 AM and 10:20 AM Central Time, Google Drive began its June 4th Service Disruption.
According to Down Detector, one massive amount of problems with Google services - 200 in an hour for Drive, more than likely - have been reported in the last hour. About half as many problems were reported yesterday afternoon in a single spike, and normal amounts between then and now.
Users may not be able to access Google Docs or any other system connected directly with Google Drive this afternoon. Most users appear to be seeing the following error:
Getting Error 502 "The server encountered a temporary error and could not complete your request. Please try again in 30 seconds. That’s all we know."
Gmail appears to be seeing some error reporting as well, but for now Google Drive is the only system "officially" down according to Google itself.