For more than a year, Facebook has endured cascading crises — over Russian misinformation, data privacy and abusive content — that transformed the Silicon Valley icon into an embattled giant accused of corporate overreach and negligence.

An investigation by The New York Times revealed how Facebook fought back against its critics: with delays, denials and a full-bore campaign in Washington. Here are six takeaways.

Facebook knew about Russian interference

In fall 2016, Mark Zuckerberg, Facebook’s chief executive, was publicly declaring it a “crazy idea” that his company had played a role in deciding the election. But security experts at the company already knew otherwise.

They found signs as early as spring 2016 that Russian hackers were poking around the Facebook accounts of people linked to American presidential campaigns. Months later, they saw Russian-controlled accounts sharing information from hacked Democratic emails with reporters. Facebook accumulated evidence of Russian activity for over a year before executives opted to share what they knew with the public — and even their own board of directors.