Hi, I've noticed a very odd behaviour with Firefox Monitor (FM), which I started using today: I 've created my Firefox account quite some time ago using my email address SchmidtSt@web.de (written with 2 upper case "S") as User-ID. When I signed up for FM today, it told me "0 breaches" which I found odd since I know for sure from haveIbeenpwned.com that this email address had been breached on last.fm (and 3 further "unverified" breaches). So I added another email address I'm using, Schmidt_St@hotmail.com (again, out of habit) written with 2 upper case "S". And again, to my surprise: "0 breaches" - ?!? That one, too, had been breached on last.fm, and additionally on Verifications.io. Thus I tried adding these two email addresses written in lower case only - and guess what? Now it works ... I think you should fix this, since the UI of haveIbeenpwned.com has no problem with using upper case letters in email addresses (and for email addresses it usually makes no difference if you write them lower or upper case). Cheers and best regards, Steffen Schmidt.