A number of ways not to lock a door...

... found over the last years on the Internet.

I hope this one is in good humour and not meant seriously.

I'm not so certain about this one...

And this is a wonderful example that "more security" is not necessarily more security. In fact, it reduces the problem of having to pick a door lock to the problem of having to pick any of these door locks, making it only as secure as the most insecure of them. The larger the number of locks, the larger the probability that one of them sucks...


-- Birgit