There are a few basic tenets of password security experts typically advise. A good password is eight digits or longer and uses a variety of letters, symbol, and numbers. You should, experts say, use a different password for every Web site to make it harder for hackers to compromise multiple accounts. Perhaps Facebook C.E.O. Mark Zuckerberg, billionaire millennial dad, could stand to learn a thing or two from security experts: over the weekend, Zuckerberg’s Twitter and Pinterest accounts were hacked, with a group called OurMine Team claiming responsibility.

“Hey @finkd we got access to your Twitter & Instagram & Pinterest, we are just testing your security, please dm (direct message) us,” now-deleted tweets from Zuckerberg’s @finkd Twitter handle read, according to CNBC. “You were in Linkedin Database with the password ‘dadada’!”

Yes, the 32-year-old Facebook founder, worth $51.2 billion, had a couple of social media accounts compromised by reusing “dadada,” which is a fitting password for the new dad. (Was “dadada” baby Max’s first word?) Zuckerberg’s Facebook and Instagram accounts were unaffected by the hack, Facebook told VentureBeat. Twitter temporarily deactivated Zuckerberg’s Twitter account (which he barely uses, anyway), and then reactivated it with the suspect tweets deleted.

It’s unclear how OurMine Team was able to hack the accounts, but the group claims it’s thanks to the recent LinkedIn password breach. Last month, millions of LinkedIn users had their information leaked. The leak contained more than 160 million user passwords, and likely was the result of a 2012 breach of user data, according to LinkedIn. LinkedIn contacted affected users after the password dump, alerting them to change their passwords. But because Zuckerberg apparently used the same password for multiple social media platforms, hackers were able to figure out how to access his Twitter and Pinterest accounts. Next time, Mark, try using a few numbers and symbols in your password, too. “Dadada” is making the dad jokes all too easy.