I still remembered my id from all those years ago, 1569200. I was excited to read others were logging in with their old numbers, so I tried the password I thought I had used, but no luck.

Feeling adventurous, I dug through my archives and found my old ICQ database and followed https://sec.sipsik.net/tuts/net/icq.txt and used the code at https://web.archive.org/web/20070209002044/https://rejetto.c... to decrypt my password...

Sadly it was the one I had tried :( It was a fun trip through nostalgia at least!