Facebook allows programmers to look up a user by their account number (ID), with a very simple URL scheme.
Usually Facebook IDs aren’t well known so this is not a huge security issue. However, in the early days of Facebook, the ID was a simple auto-incrementing number.
This leads to a hack which fits in a tweet: early Facebook users in order.
You can try it yourself right away on Mac or Unix machines. (Windows machines probably won’t have
You’ll get something like this:
1 2 3 4 5 6 7 8 9 10 11 12 13 14
And so on, for as long as you want.
Some of those names are already recognizable as early Facebook employees who’ve gone on to other things.
You’re only getting public information, so it’s mostly harmless, and could be of interest to researchers looking into the early history of the social network.
Fun fact: Eduardo Saverin doesn’t appear until #41.