The commander of Israel’s military surveillance agency, Unit 8200, is facing fresh embarrassment after it emerged that an extensive digital trail identifying him as a senior intelligence official has been exposed online for years. The Guardian revealed on Friday how Yossi Sariel, whose name had been protected by the Israeli state, inadvertently disclosed his identity online in a security lapse linked to a book published under a pen name in 2021. Details have now emerged that suggest Sariel’s position as the elite unit’s commander were inadvertently disclosed in a government document posted online two years ago. The Guardian has also now identified a string of social media accounts used by the head of Unit 8200, the secretive cyber intelligence division of the Israel Defense Forces (IDF). Sariel even left traces of his activity on the Hebrew-language Wikipedia, where he used his real name and edited pages ranging from Louis XIV of France to an entry titled “the problem of Palestinian refugees”. The new details about Sariel’s apparently casual approach to online security are likely to add further pressure on the intelligence boss. They are particularly embarrassing because Sariel has styled himself as a pioneer of artificial intelligence, seeking new ways that surveillance systems can process the digital footprints of daily lives. Until he was unmasked last week, Sariel’s identity was a state secret in Israel. Journalists in the country were prevented from naming him despite a major controversy brewing over his leadership of Unit 8200 and its failure to foresee or prevent Hamas’s deadly 7 October attacks. In a surprising lapse in security, the Unit 8200 commander included an anonymous email address in an electronic version of his 2021 book, The Human Machine Team, about the use of AI in military intelligence. The address can be easily traced to a private Google account created in Sariel’s name. The Guardian’s revelation has been met with consternation in Israel, where Sariel is facing increasing pressure. Yossi Melman, a longtime chronicler of Israel’s intelligence services, wrote that Sariel’s exposure was a “huge embarrassment” and “only adds to his personal responsibility and the colossal failure of his unit” to prevent the Hamas-led attacks last year. The law professor and Unit 8200 veteran Yuval Elbashan argued that Sariel had demonstrated a “recklessness and lack of professionalism”. He said he found it “hard to believe” that Sariel had “dared to publish on Amazon a book about an advanced secret field that he was entrusted with as part of his work”. Last week, the IDF said the book was “approved according to the guidelines in Israel prior to its publication”. It has acknowledged the book’s exposure of Sariel’s personal details was “a mistake”, adding: “The issue will be examined to prevent the recurrence of similar cases in the future.” However responding to criticism this week, the IDF added: “The commander of the 8200 Unit is an honoured officer, leading his unit in wartime. Any claims and attempts to portray his behaviour as reckless or irresponsible are baseless.” It is now known that Sariel’s identity and his links to the intelligence unit, which is comparable to the US National Security Agency or GCHQ in the UK, had been compromised for several years. In a document available online since at least February 2022, his name and position – “Yossi Sariel Commander 8200” – were inadvertently included in a register of meetings held by a senior official at Israel’s ministry of construction and housing. The IDF said the document was published by the government ministry “without coordination with the IDF and [Sariel] was not aware of it”. It also appears that Sariel maintained a number of social media accounts under his own name. The Guardian identified accounts apparently connected to him on Facebook, Instagram, Skype and LinkedIn. The Facebook account, which was deleted late on Friday, appeared to include a photo of his face and was associated with a page belonging to an alumni group for Unit 8200 officers. The LinkedIn profile listed his rank of brigadier general and could be traced to accounts linked to the military intelligence unit. On Wikipedia, Sariel’s historical activity – also deleted in recent days – included edits to pages about the IDF’s Golani Brigade and another on the Palestinian right to return. His account, was created and used in the 2000s and could be linked to his role as co-founder of a group of reform-minded intelligence officers known as “the Choir”. The account listed an email address created using his first and last name. In a post from 2006, a fellow Wikipedia user noticed the intelligence official’s activity on the website was “very public” and warned: “It’s possible that your personal details will be misused.” In a statement, the IDF said Sariel had created the Wikipedia page “as part of an academic group project” while a student. They said IDF officers are permitted to maintain private social media accounts but Sariel has now “decided to delete his account for his family’s safety”. The technology described by Sariel in his 2021 book closely resembles AI-powered target recommendation systems used by the IDF, such as the Gospel and Lavender, details of which have been revealed in reports by the Israeli-Palestinian publication +972 magazine, its Hebrew-language outlet Local Call and the Guardian. The commander is considered a key architect behind the IDF’s use of such AI-powered target recommendation systems in its bombardment of Gaza, which has killed more than 33,000 people, according to the territory’s Hamas-run health ministry.