@Karla Sleutel What kind of technical knowledge do you have that lets you dismiss this serious issue with a "the user could be from a troublesome location"?
You clearly haven’t, because if you had, you would have immediately discovered that the registration process is broken due to the captcha missing. The captcha provider (KeyCaptcha) has shut down their service.
Instead, you chose to derail the discussion by nitpicking something that wasn’t even a mistake. And your claim about Europeans being taught only British English is downright absurd. I know plenty of people who are neither British nor American and still use American English and its spelling.
Anyway, thanks to everyone who actually helped resolve this issue.