Thanks for sharing Celia, but for most of us this won’t be super helpful. If you use email aliases for all your accounts then this should not really have a large impact and neither the tool will he helpful as you can only scan for one email at the time, although it may be good to run some old email addresses through it, yet I would be sceptical given it’s run by the police. It would have been better if they had contributed it to HIBP where one can also get all emails in a single domain you control.
There is a discussion on fingerprinting here: Browser fingerprinting/tracking overview. Also many of the recommendations are made with this in mind.