I used the site to learn about ethical hacking, the various holes and errors that you can make when setting up a site.

As you can see by the screenshot above, there's some coding skills, detective work and trial and error needed to advance.

Each level gets more and more difficult.

I had to stop when my health deteriorated, but I did manage to reach level 5.

If you look at the mirrored Wikipedia page above, you'll see that there has been a rift between the founders over the ethics of the site.

It is lots of fun. Most stackers will whizz through the levels like a breeze.

So, upgrade your cowboy hat for an even whiter (cowboy) hat, share your experiences, try the levels, but don't identify yourself too much - after all you are meant to be getting better opsec skills, not worse!