ICQ

ICQ was the first ever popular instant messenger. It was based on Talk (specifically Y-Talk), which was a very basic program designed for Unix. Their aim was to make "Y-Talk for Windows". It has since expanded well beyond that.

Y-Talk worked like this:

talk john@smith.net (other end) accept jack@jones.net

Then your entire window would be half you and half them, with a line down the middle. Then you just typed.

CTRL C to end.

The people who had the idea for ICQ loved this idea, but sought to improve on it. They wanted the same simplicity, but not to dominate the screen. Y-Talk was great but it was annoying in that it stopped whatever else you were doing. They wanted you to be able to keep doing something else. They wanted it to keep its file transfer possibilities, but also allow searching and more than that.

ICQ was prone to hacking in its early days (and to some extent still today), which was largely due to ICQ's development initially being public domain. Many of the people involved in the creation of ICQ were volunteers who found out about it from newsgroups and the like. As such, when it was finally released, most of its programming details were well known, and its security holes were able to be abused by hackers.

Some months before it began, a group of people decided to take ownership of the program, using it for great profit. They completed development in secret.

Many people in the computing industry felt betrayed by this. They had contributed to its development yet received no reward for it and instead a few people took their good work to make millions.

As revenge for the feeling of betrayal, a number of computing hackers decided to hack various people who used ICQ.

In its early days in particular, people using ICQ were routinely hacked, often having their whole computer taken over.

Whilst most of the early security holes have now been fixed, the main reason that ICQ is more secure now is that there is no longer any major reason to hack. It has been too many years now and there is no longer a reason to hack it.