The Users page seems to display all the users on a single line, as shown in the picture below:
For the record, I am using a Macbook (early 2015), running macOS 10.12.2 running Safari 10.0.2. The bug appears to occur on all SE sites. Other users there weren't able to reproduce this, so I think it might be some of the new CSS changes which is incompatible with Safari 10.
This one seems to have been fixed... But everything is heavily misaligned now: