To avoid situations where a link given by others, or accidentally embedded on the SL websites, change the site language for the user, please make it so that a special query is required to change language, and otherwise the language parameters are ignored.

The special query could look like.... https://secondlife.com/my/?SetLang=en-US --- if it's just "lang" then it should be ignored.

I have previously filed this bug, but it's not exactly the same thing: https://feedback.secondlife.com/web-bugs/p/remove-the-language-from-the-urls-on-mp