https://motherboard.vice.com/en_us/article/a3y4n5/zuckerberg-facebook-identified-notified-campaigns-russian-hackers-in-2016

Facebook detected Russian government hackers targeting the Facebook accounts of campaign officials before the 2016 presidential election, Mark Zuckerberg revealed during a congressional hearing on Tuesday.

The company founder said that the company spotted the hackers’ attempts and then alerted the campaigns that the hackers were going after them. In response to a question by Sen. Dianne Feinstein about Russian interference in the US elections, Zuckerberg said Facebook thought people with political connections might get hacked, but didn’t expect a disinformation campaign.