This episode contains strong language.

The pro-Trump mob that stormed the Capitol on Wednesday made their plans in plain sight. They organized on social media platforms and spoke openly of their intentions to occupy the Capitol.

But leaders in Washington opted for a modest law enforcement presence. In the aftermath, those security preparations are attracting intense scrutiny.

Today, we explore how the events of Jan. 6 could have happened.

Guest: Sheera Frenkel, who covers cybersecurity for The New York Times; Zolan Kanno-Youngs, a homeland security correspondent for The Times.

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Background reading:

• Inside Trump supporters’ online echo chambers, the chaos of Jan. 6 could be seen coming.
• Failures by the police have spurred resignations and complaints of double standards.
• During the storming of the Capitol, social media sites were used by the mob to share information, including directions on which streets to take to avoid the police and which tools to bring to help pry open doors.

For more information on today’s episode, visit nytimes.com/thedaily