From the Document: "In September 2020, al-Qaʻida published an English-language translation of its 3rd edition of 'One Ummah' magazine featuring a new foreword threatening 'Charlie Hebdo' staff members for republishing its cartoons of the Prophet Muhammad. Awareness of terrorist messaging, particularly those around significant dates, can help identify and assess possible threats. Although terrorist operational readiness typically dictates the timing and targets of planned terrorist attacks, commemorations remain targets because of their iconic or psychological value. Alternatively, opportunistic attacks have limited pre-attack indicators, given these attacks occur with little to no warning. Evaluating terrorist commemorative messaging is important as a preventative measure."
Office of the Director of National Intelligence: https://www.dni.gov/