A British man accused of plotting a terror attack may have targeted Tony Blair and wife Cherie, jurors in his partly-secret terror trial heard.
Erol Incedal (26), from London, may also have been looking at a "Mumbai-style" atrocity, according to messages on his computer, the Old Bailey was told.
But the alleged plot was scuppered after police stopped Incedal's car for a motoring offence and planted a bugging device which picked up chatter about "bin Laden, Syria and jihad".
Incedal denies preparing acts of terrorism and possessing a document entitled Bomb Making on a memory card.
Jurors were told his co-defendant, Mounir Rarmoul-Bouhadjar, also 26, from London, who was known as CD, has pleaded guilty to possessing a terrorist document.
Opening the case against Incedal, prosecutor Richard Whittam QC said: "You will hear that he was actively engaged with another or others who were abroad.
"The prosecution case is that such engagement was for an act or acts of terrorism either against a limited number of individuals of significance or a more wide-ranging and indiscriminate attack such as the one in Mumbai in 2008."
When police first stopped Incedal's black Mercedes on September 30, 2013, they found an Acer laptop computer, a notebook and a Versace glasses case which contained a scrap of paper with the Blairs' address on it.
During the search, police planted a bugging device in the car which picked up conversations that give a "flavour" of what was going on in the following weeks, Mr Whittam said. Armed police swooped on the car on October 13 last year as Incedal was driving and co-defendant Rarmoul-Bouhadjar in the passenger seat.
Incedal was arrested on suspicion of being a terrorist and told to hand over the pin numbers for his two mobiles.
Mr Whittam told the court that Incedal's phone contained various images of a synagogue and YouTube page in support of the Islamic State in Iraq.
The iPhone had internet searches in English and Arabic for the Islamic State in Iraq and had the black flag of Islam as a screensaver.
In the afternoon, the trial continued in secret with journalists allowed to attend but not to report on the proceedings.
The trial is expected to go on for four-to-six weeks.