A radicalised man shared terrorist propaganda using a mobile phone emblazoned with the black flag of the Islamic State group, a court heard.
Taha Hussain, 21, from Slough is on trial accused of nine counts of disseminating terror documents via smart phone apps including WhatsApp.
The Old Bailey heard he became increasingly extreme in the two years before his arrest in August last year.
The defendant denies all the charges against him.
Mr Hussain is also charged with one count of encouraging terrorism through posts on Twitter.
When police seized his mobile phone, they found the black flag of IS on his screen saver and his PIN number was 9117 - in apparent homage to the 9/11 and 7/7 terror attacks, the court heard.
Prosecutor Mark Paltenghi told jurors on Thursday: "It may be that this is a combination of the dates of two of the most significant acts of terrorism this century - the attacks upon the Twin Towers in New York and other targets in America on September 11, 2001, and part of the date of the London bombings on July 7, 2005."
Over 11 months, Mr Hussain is accused of distributing YouTube videos and audio files on topics including Charlie Hebdo and bombings in Britain and the US as well as a copy of an IS magazine.
Mr Paltenghi said: "In essence, it is alleged that when all this material was sent it was done with the intention that it would be understood by its recipients as a direct or indirect encouragement to the commission, instigation or preparation of acts of terrorism."
The trial continues.
