He won a 2012 National Magazine Award for reporting on biased FBI training materials and shared in a 2014 Pulitzer Prize for his coverage of the 2013 global surveillance disclosures.

Born to a Jewish family on June 1, 1980, Ackerman grew up in a politically active household and started attending protests at age ten.

[33][34] In July 2010, The Daily Caller reported on Ackerman's membership in JournoList, a private Google Groups forum for discussing politics and the news media created by Ezra Klein in February 2007.

[48] In 2011, he won the National Magazine Award for Digital Media for his series on exposing the use of Islamophobic material to train recruits in counterterrorism at the FBI Academy in Quantico, Virginia.

[49][50][51] After the revelations, at the mandate of the Obama administration, the FBI launched an investigation and turned to the U.S. Army's Combating Terrorism Center at West Point before eventually purging the materials.

[52] In a January 2012 column for Tablet magazine, Ackerman expressed disagreement with the use of the term "Israel Firster", writing, "if you can’t do it without sounding like Pat Buchanan, who has nothing but antipathy and contempt for Jews, then you’ve lost the debate.

"[53] Identifying himself as being part of the Jewish left, Ackerman noted the term was first used by far-right activist Willis Carto and neo-Nazi David Duke.

[57] The article garnered the attention of British comedian and satirist Armando Iannucci, co-creator of the Alan Partridge character, who contacted Ackerman to work as a political consultant on his film In The Loop, which lampoons the British-U.S. special relationship during the Iraq War.

[60] During his onboarding process, Ackerman's job orientation functioned as cover for a briefing on the 2013 global surveillance disclosures, which the publication had just received from Edward Snowden.

[61] He contributed to several stories on the NSA’s surveillance programs based on these leaks, leading to The Guardian winning the 2014 Pulitzer Prize for Public Service.

[72] Ackerman joined The Daily Beast as a senior national security correspondent in May 2017, reuniting with his former editor from Wired, Noah Shachtman.

[73][74] In 2021, Ackerman stepped down at The Daily Beast[75] and launched Forever Wars, a Substack newsletter focused on international politics through a socialist lens, critiquing American militarism and exceptionalism.