The fact that the U.S. government has been snooping on its citizens is no more hidden. However, the revelations about the scale of it is still not publicly known — a new revelation might be key to discovering just how much surveillance has taken place.

The Wiretap Report 2016, published by the United States Courts revealed that around 3.3 million phone calls were tapped in just a period of two months, as part of a federal narcotics investigation.

"The federal wiretap with the most intercepts occurred during a narcotics investigation in the Middle District of Pennsylvania and resulted in the interception of 3,292,385 cell phone conversations or messages over 60 days," said the report.

Read: Bush Wiretapping Legal Memos: Stellar Wind Surveillance Authorized Due To ‘Armed Conflict With Al Qaeda'

The phone tapping was authorized by a single wiretap order. The order was signed to help the authorities track 26 individuals suspected of illegal drug trafficking and narcotics-related activities in Pennsylvania.

However, the investigation cost $335,000 to the taxpayer and led only to a dozen arrests. The surveillance effort neither captured any intercepts nor did it bring anyone to trial or convicted. Other details about the wiretapping are not available since the court records have been sealed.  The order might be the largest one for a single investigation and the number of Americans, whose phone calls were listened to, is not available either.

The revelation has gathered criticism from privacy advocates. Albert Gidari, a former privacy lawyer who now serves as director of privacy at Stanford Law School's Center for Internet and Society, told ZDnet

"They spent a fortune tracking 26 people and recording three million conversations and apparently got nothing, I'd love to see the probable cause affidavit for that one and wonder what the court thought on its 10 day reviews when zip came in. … "I'm not surprised by the results because on average, a very very low percentage of conversations are incriminating, and a very very low percent results in conviction."

The justice department has declined to comment on the investigation.

What is evident though is that even when wiretap orders are issued for an investigation, there might be many individuals whose privacy would have been violated, to no avail. The rate of success of a spying operation is abysmal, but the number of people whose privacy rights have been taken away is very big.

And it is not just phone calls — most communication nowadays is digital, which means that it has digital rather than analog signals. These can be easily interfered with – a single malware can give someone the access to all the information on your computer.  And it is not even just that, WikiLeaks has repeatedly revealed different kind of tactics used by the government, one of which was listening in to people by hacking into their smart TVs.

Read: Was My Samsung TV Hacked?: How To Tell If Your Smart TV Was Compromised By CIA Weeping Angel Hack

The world changed when former President George W. Bush signed the Patriot Act after 9/11 and seems to be moving further into an age where the government snooping its own citizens is becoming common. The only way this can change is if the legislation to protect citizens’ privacy rights is enacted and boundaries between snooping and criminal investigation are established.

President Donald Trump, who himself accused former President Barack Obama of wiretapping the Trump Tower and first claimed to have taped his conversations with FBI Director James Comey and then denied it, is yet to act in this direction.