Are there any on-going issues right now with SE infrastructure?
Both chat and sites have been experiencing intermittent issues for a few hours. This has been reported on Stack Overflow (main, meta and chat), as well as multiple *.stackexchange sites.
I'd put this down to widespread internet issues with CloudFlare and CenturyLink but rather than failing to connect to SE at all a maintenance message is being shown:
Screenshot provided courtesy of Samuel Liew who wasn't able to access the site