If you're using chrome, the omnibar seems to send out whatever you type to (google's?) server for search suggestion, so you shouldn't do that if you're copying

If you're using chrome, the omnibar seems to send out whatever you type to (google's?) server for search suggestion, so you shouldn't do that if you're copying sensitive data. You can use ⌘+shift+v to paste the text without formatting (and without sending your data to some random servers).