Recently the Village Pump (technical) section has raised an issue that links books.google.com is changed to gg.sxbb.me (See [[ https://zh.wikipedia.org/w/index.php?title=Wikipedia:%E4%BA%92%E5%8A%A9%E5%AE%A2%E6%A0%88/%E6%8A%80%E6%9C%AF&oldid=61090279#gg.sxbb.me | here ]] for the discussion). The editor who performed the edits claimed that the edits are changed due to VisualEditor, but is in fact changed by the mirror website.
Such an incident is potentially dangerous as the mirror site can gain the user credential, which can be used to perform harmful edits that are not done by the users themselves, breaking the intention of HSTS. This also decreases the trust of some users about Wikimedia as they think the edits are changed by Wikimedia's tools/extensions, which appears in this case.
We are glad that. this time, the edits from the mirror site are not intentionally harmful, but maybe not next time. I hope the security team can evaluate such situation.