To this day, I still remember my ICQ number from back in the nineties. However, unfortunately the same doesn't apply to the password and I can't seem to be able to reset it.
> I did have someone try to take it over about a decade ago
I either didn't have mine linked to a recovery email or lost access to that email account. Tried to get back into the account somewhere in the aughts but no longer knew the password, and thus was out of luck. But then I discovered some years later that someone else had taken it over, as it was associated with some Russian thing. Oh well.
I have a few friends from back in ICQs heyday that still use it. It's kind of a running joke. One of us will fire up a client and login, then email the others asking, "where in the hell is everyone" and we'll use it for a week, then it fades again, until a few years later, someone fires up a client, and emails the others asking, "where in the hell is everyone"... ;)
I also like keeping ancient accounts. I've been on some form of the internet since 300bps modems, so I have a number of ancient accounts that I'll pile up, and when I die, they'll be given to my partner, so they can hang on to them, until they pass. Some day, 371 years down the road, a small child will hold a sheet of paper with these accounts on them and wonder what in the hell was wrong with people 400 years prior. lol
edit: That compuserve line wasn't a joke. I still know my username/password from those days.