Between the NSA’s power and the IRS’s revenge, how can Americans not be worried about the opinions they express?

Feel like Big Brother is watching you these days? You’re not alone.

“This is not some far-out Orwellian scenario,” wrote the late William Safire of The New York Times in 2002, in the panicky aftermath of 9/11. “Here is what will happen to you: Every purchase you make with a credit card, every magazine subscription you buy and medical prescription you fill, every Web site you visit and e-mail you send or receive . . . will go into what the Defense Department describes as ‘a virtual, centralized grand database.’ ”

Twelve years on, this is the world we live in, but worse. Through a combination of fear, cowardice, political opportunism and bureaucratic metastasis, the erstwhile land of the free has been transformed into a nation of closely watched subjects — a country of 300 million potential criminals, whose daily activities need constant monitoring.

Once the most secret of organizations, the NSA has become even more famous than the CIA, the public face of Big Brother himself. At its headquarters on Savage Road in Fort Meade, Md., its omnivorous Black Widow supercomputer hoovers up data both foreign and domestic, while its new $2 billion data center near Bluffdale, Utah — the highly classified Intelligence Community Comprehensive National Cybersecurity Initiative Data Center — houses, well, just about everything. As James Bamford wrote in Wired magazine two years ago, as the center was being completed:

“Flowing through its servers and routers and stored in near-bottomless databases will be all forms of communication, including the complete contents of private e-mails, cellphone calls, and Google searches, as well as all sorts of personal data trails — parking receipts, travel itineraries, bookstore purchases, and other digital ‘pocket litter.’ ”

The question is: To what end?

The administration says: Trust us, we’re only after the bad guys.

But considering President Obama’s track record, how is “trust us” a consoling argument?

The IRS admitted targeting conservative groups before the 2012 election, subjecting them to extra scrutiny and delaying their nonprofit status. One group, Friends of Abe, says its application was held up for two years and they were asked to hand over a list of its members. Another, the National Organization for Marriage, alleged that the IRS leaked its 2008 tax return and donor lists.

Meanwhile, a number of Obama’s critics have noticed how audits seem to follow their outspokenness — a coincidence, to be sure.

But how about conservative filmmaker Dinesh D’Souza, who was charged with a felony for allegedly making illegal campaign contributions — something that warranted a much lesser charge for other defendants? Is his prosecution just a coincidence?

Harvard Law professor Alan Dershowitz doesn’t think so. “The idea of charging him with a felony for this doesn’t sound like a proper exercise of prosecutorial discretion,” he said. “I can’t help but think that [D’Souza’s] politics have something to do with it . . . It smacks of selective prosecution.”

One could conclude that the administration can’t keep private information private — and is happy to seek retribution on those who disagree with it.

The irony is, all this snooping may not really be necessary. These days, Americans can’t expose themselves enough: Their smartphones constantly broadcast their whereabouts to law enforcement, while millions cheerfully post intimate personal details and embarrassing photographs of themselves and their families on social media.

The fact is, privacy has become a thing of the past, destroyed by the rise of information technology, the force of government, and the willing surrender of the citizenry.

But how many Americans’ hands are pausing over a keyboard these days, wondering if posting their opinion over Facebook isn’t putting themselves at risk?

The NSA revelations and the IRS scandal have sent a chill through freedom of speech and expression in this country.

“Trust us” cannot be the answer.

As the old saying goes: Just because you’re paranoid doesn’t mean they’re not out to get you.