An FBI informant warned the bureau that a tweet sent by former President Trump before January 6 about a protest at the Capitol was considered by the far-right as a "call to arms." NBC's Ryan Reilly has details. » Subscribe to MSNBC: http://on.msnbc.com/SubscribeTomsnbc Follow MSNBC Show Blogs MaddowBlog: https://www.msnbc.com/maddowblog ReidOut Blog: https://www.msnbc.com/reidoutblog MSNBC delivers breaking news, in-depth analysis of politics headlines, as well as commentary and informed perspectives. Find video clips and segments from The Rachel Maddow Show, Morning Joe, The Beat with Ari Melber, Deadline: White House, The ReidOut, All In, Last Word, 11th Hour, and Alex Wagner who brings her breadth of reporting experience to MSNBC primetime. Watch “Alex Wagner Tonight” Tuesday through Friday at 9pm Eastern. Connect with MSNBC Online Visit msnbc.com: http://on.msnbc.com/Readmsnbc Subscribe to the MSNBC Daily Newsletter: MSNBC.com/NewslettersYouTube Find MSNBC on Facebook: http://on.msnbc.com/Likemsnbc Follow MSNBC on Twitter: http://on.msnbc.com/Followmsnbc Follow MSNBC on Instagram: http://on.msnbc.com/Instamsnbc Informant Warned FBI Before Jan. 6 That Far-Right Saw Trump Tweet As 'Call To Arms'