[TOMT][Books][Early 2000s] - YA Internet Thriller/Mystery Series w/Email Address in Title?

Today something (who knows what) triggered a deeply-ingrained memory and it's driving me crazy trying to 'unlock' it. I've eked out a few clues, but have a terrible memory and the few flashes I do get are usually more visual, so I don't have a ton to go on content-wise here. I know if i see a pic I'd recognize the books immediately though!

I'm looking for a book series - fiction, YA, mystery/thriller genre with "internet" theme, ~early 2000s; USA. I am almost certain the book(s) and/or series title contained an email address or URL.

Visually the books were mostly black except for a small-ish title written in 'command line' font (my brain is giving Swimfan/Matrix code vibes?). Each book's title had its own color - red, blue, green; Gillian Flynn's books pop into mind as similar color scheme.

I’m pretty sure there were at least 3, maybe up to ~6-7? books in the series.

...aaand that's all I got, folks. Please put my ADHD obsessing brain to rest and LMK if this sounds familiar!