Twitter's site crashed on Thursday at about 3pm BST due to a "denial of service" attack – thousands of remote-controlled virus-infected PCs trying to contact the site.
Though the site came back up after an hour, the company said it was "continuing to defend against and recover from this attack".
As a result lunch plans, breaking news, links to obscure web pages, news about your cat, the thoughts of celebrities, and wondering on Twitter why your tweets aren't appearing – all had to be put on hold. The loss will have been felt most keenly in London, which Twitter's co-founder and chief executive Evan Williams revealed on Wednesday has more Twitter users than any other city in the world.
The company's status blog says that: "We are defending against a denial-of-service attack, and will update status again shortly."
Wonder if this has anything to do with international politics?