Today me and some other users have observed that the reputation ranking page doesn't allow to navigate past page 999.
For example, https://meta.stackexchange.com/users?page=1111&tab=reputation&filter=week shows a page:
We're sorry... There are an unusual number of requests coming from this IP address.
To protect our users, we can't process any more requests from this IP address right now.
We'll restore access as quickly as possible, so try again soon.
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