Mark Zuckerberg's embarrassingly insecure password revealed: dadada

Never reuse passwords. Use a mix of alphanumeric characters, symbols, and different casing. Change passwords regularly. These are just a few of the rules Mark Zuckerberg apparently violated with accounts on other social networking sites.

Hackers briefly took over the Facebook founder's Twitter, Pinterest, and Instagram accounts, all using information reportedly hacked from the massive LinkedIn breach.

The accounts were briefly restored, but not before the hackers asked him to reach out ... and revealed that his password was the comically (or perhaps tragically) insecure "dadada".

If the chief executive of one of the most influential tech firms doesn't take passwords seriously, how much danger is your company in, particularly if attackers keep quiet about their find instead of broadcasting it?