I turned on my laptop today and suddenly got a lot of Codeforces notifications.

Some of them said things like:

"Hello, I hacked CF" "This is an Emergency Alert Broadcast" "I can only send announcements" random usernames and some other strange strings All of them are general announcement notifications.

But when I opened the site I couldn’t find any blog or announcement about it.

Did this happen to anyone else? Was it a bug/test or something else?