The NSA's state surveillance programs are anti-democratic and unconstitutional. They could be the most serious attacks on free speech we've ever seen.

On Sunday, U.K. intelligence officers held Guardian journalist Glenn Greenwald's partner David Miranda for nine hours at Heathrow Airport, confiscating his laptop, phone and documents and even forcing him to reveal his passwords to online accounts.

And on Monday, we learned that the British intelligence unit GCHQ demanded that the Guardian return all of the data related to Edward Snowden's leaks. The agents stormed the Guardian's London headquarters–even though the NSA reporting is flowing from the paper's New York office–and oversaw the destruction of journalists' computers and hard drives.

These were not just overly aggressive police actions. They were political moves designed to intimidate journalists and silence dissent.

"You've had your debate. There's no need to write any more," a British agent told Guardian Editor-in-Chief Alan Rusbridger.

This kind of surveillance doesn't just silence professional journalists. It affects all of us. As we now know, the NSA — with a big assist from companies like AT&T, Facebook, Google and Verizon, who were already busy tracking us — uses programs like PRISM and XKeyscore to build files of everyone's contacts, communications, movements and browsing habits.

It may be tempting to shrug off these details. "What's it matter to me?" some ask. "I'm doing nothing wrong."

But now we're seeing the trickle-down effects of this surveillance. Email providers have closed their doors rather than comply with secret government requests. And Groklaw, a 10-year-old blog that covers the ins and outs of tech law, is also shutting down, citing the climate of expanded surveillance as one reason.

"I don't know how to function in such an atmosphere" of the NSA "collecting and screening everything we say to one another," wrote Groklaw founder Pamela Jones. Since Groklaw is built on collaborations that often take place over email, Jones says she can't continue her work knowing that her communications aren't private.

The chilling of free speech isn't just a consequence of surveillance. It's also a motive. We adopt the art of self-censorship, closing down blogs, watching what we say on Facebook, forgoing "private" email for fear that any errant word may come back to haunt us in one, five or fifteen 15 years. "The mind's tendency to still feel observed when alone… can be inhibiting," writes Janna Malamud Smith. Indeed.

Peggy Noonan, describing a conversation with longtime civil liberties advocate Nat Hentoff, writes that "the inevitable end of surveillance is self-censorship."

Hentoff stressed that privacy invasions of this magnitude are "attempts to try to change who we are as Americans." In fact, they are attempts to define who we are as human beings.

Our human rights to speak and to communicate, to report and to assemble, are all at stake. "What I do know is it's not possible to be fully human if you are being surveilled 24/7," writes Groklaw's Jones.

We must return to a place where we feel that we can speak freely without consequence.

We must roll back the NSA's surveillance apparatus.