Before 2013, data sent between Google data-centers were in plaintext (!!!) because Google incorrectly assumed that the their private fiber network was actually private[0].

So if you used Gmail or communicated with people who used Gmail before 2013, then a copy of your communications are backuped up in Utah[1] right now.

[0] https://www.wired.com/2013/10/nsa-hacked-yahoo-google-cables

[1] https://en.wikipedia.org/wiki/Utah_Data_Center

Quickbooks Online would also be horrific

Which is why nobody should use Quickbooks Online.

I think a mature state of mind is that you should assume those systems are compromised.