Non-ASCII characters not rendered in the recent topics list

There is a recent topic with non-ASCII title (Cyrillic, to be exact).
It is displayed in the recent topics list, however, the title is rendered improperly (see the screenshot).

This is not the browser's text encoding - changing it doesn't fix the title in the sidebar, and breaks the rest of the page.

Code of the broken link:
Those "?" are ordinary question marks (0x3F).

I'm not going to support cyrillic text or non ascii characters - if people want to use weird inputs like from their mobile phone etc. they do so at their own peril.

Why? We're not in the 90s anymore. Unicode support is the standard.