~10 years ago I discovered Google doing steganography and their e-mails by accident. I was searching gmail for an e-mail message using a word I knew was definitely in the message but it was not being found. Eventually I found the e-mail and confirmed the word was definitely there. Ctrl+F and type the word, it's not found. Turned out there were random Cyrillic characters mixed through the message. Confirmed with others their messages similarly had random Cyrillic characters, but different from my own.
Always found it ironic that their own products (gmail/chrome) gave away their attempts at steganography.
What's the context of this? Were/are you a Googler and this was in internal emails? Or was this just emails Google sends to customers? (I'm choosing to assume that this isn't about random emails other people send to Gmail addresses, that Google just messes with this way.)
Yea, this was for internal communication, presumably to catch leaks. I've not worked there for 10 years now so I can't speak to whether they're still doing anything like this internally but I wouldn't be surprised.
Always found it ironic that their own products (gmail/chrome) gave away their attempts at steganography.