[Zak]

I've noticed Google's web properties are particularly bad about this. I'm logged into an account - they know what language I want my search results in because I told them in my account preferences, but if my IP geolocation says I'm in a different country, I must want the UI in the local language, right?

[teachrdan]

This used to be especially bad in Google Maps. Just because I'm in Japan doesn't mean that I, the US-ian logged into their English-language Google account, can suddenly read Japanese!

If the Gmail UI is in Japanese I can probably muddle through. If train lines and street names are in kanji I'm probably effed.

(Maps has since improved language detection.)