Session based lockout as going to another browser means that you can log in again, so getting clouldflare lockout as page loading stalls and eventually comes back with the bog standard:

Something seems to be wrong with the Internet. 

 Sorry for the inconvenience! 

 If it continues, try #moodleorg on twitter. 

To reproduce:

1. Go to a forum.
2. Click on a user's name.
3. Click on the 'Messages' button.