Nearly all of the highest-profile domestic terrorism plots in the United States since 9/11 featured the “direct involvement” of government agents or informants, a new report says.

Some of the controversial “sting” operations “were proposed or led by informants”, bordering on entrapment by law enforcement. Yet the courtroom obstacles to proving entrapment are significant, one of the reasons the stings persist.

The US government shut down a series of court cases arising from a multimillion pound business dispute in order to conceal evidence of a damning intelligence failure shortly before the 9/11 attacks, MPs were told.

Moreover, the UK government is now seeking similar powers that could be used to prevent evidence of illegal acts and embarrassing failures from emerging in court, David Davis, the former shadow home secretary, told the Commons.

A federal judge on Wednesday continued to question the FBI’s explanation for not producing videotapes associated with the 1995 Oklahoma City bombing that a Salt Lake lawyer has sought for nearly six years.

“It’s quite astounding that documents as important as these went missing and the FBI says, ‘Well, they’re gone,’” U.S. District Judge Clark Waddoups said during a motion hearing.

The US Air Force solicited private sector vendors for something called “persona management software.” Such a technology would allow single individuals to command virtual armies of fake, digital “people” across numerous social media portals.

Nine years after the terrorist attacks of 2001, the United States is assembling a vast domestic intelligence apparatus to collect information about Americans, using the FBI, local police, state homeland security offices and military criminal investigators.

The system, by far the largest and most technologically sophisticated in the nation’s history, collects, stores and analyzes information about thousands of U.S. citizens and residents, many of whom have not been accused of any wrongdoing.