Miller said many Americans don't understand how their access to information and the freedom of the press have been affected in the past few years.
"We are less free and less safe," she said, explaining that there is a "growing secrecy in the name of national security."
Miller, who spent 85 days in jail for refusing to reveal a source in the Valerie Plame case, spoke Friday morning at Kansas State University as part of the "Community Readiness Communications: Accurate Messages in Times of Crisis" conference.
Plame was a CIA agent whose identity was leaked in 2003 when her husband, former Ambassador Joseph Wilson, criticized the Bush administration's prewar intelligence on Iraq. Miller went to jail rather than reveal her source, White House aide I. Lewis "Scooter" Libby.
Miller said "no one can deny lives haven't changed since 9/11" and that national security is a concern, but the federal government has used that fear to justify eavesdropping on phone conversations and tapping into e-mails without warrants and classifying information that once was available to the public.
"More than 15 million documents were classified last year," she said, explaining that translates into 125 documents a minute. "It's intimidation by classification."
And American citizens are paying for it, she said, to the tune of $7.2 billion in fiscal year 2004.
How can an electorate be free and informed if it is denied information? Miller asked. Without a free press, such stories as the torture of prisoners at Iraq's Abu Ghraib prison, warrantless wiretapping and CIA prisons in Eastern Europe wouldn't have been reported, she said.
"People need to know what the government is doing in order to debate," she said.
Miller said the American media, however, give the federal government reason to doubt its motives and competence each time it is discovered that an article is plagiarized or gossip is reported as fact.
The blurring of entertainment and news and the relaxing of journalistic standards can be seen in online bloggers who are critical of people without giving them an opportunity to respond or who don't post corrections when they learn that what they have posted is wrong, she said.
"I'm worried about bloggers," she said. "(A post) starts as a rumor and within 24 hours it's repeated as fact."
While she advocates a federal shield law to protect mainstream journalists from divulging their sources, she doesn't favor extending that to bloggers who don't follow the standards and ethnics of the journalism industry.
Still, she wouldn't restrict a blogger's right to publish online. She said some bloggers have been invaluable in uncovering government flaws.
"I'm glad to welcome them as long as they agree to the standards," she said.