Americans are increasingly concerned about government invasion of privacy while investigating terrorism, and some ordinary citizens are finding ways to push back. The question is whether they will be successful in creating a broader populist movement.

Some are signing online petitions and threatening lawsuits. Some are pressing their Internet and phone providers to say when data is shared with the government.

But challenges lie ahead. Many lawmakers have defended the National Security Agency surveillance program — which Congress reviewed and approved in secret — even after former contractor Edward Snowden leaked their details weeks ago.

And unlike the anti-war effort during President George W. Bush's administration, government surveillance opponents tend to cut across political party lines. The cause appeals to libertarian Republicans who don't like big government and progressive liberals who like big government but favor civil liberties. Together, these voters would have little in common otherwise.

At issue is whether the government overstepped its bounds when it began collecting and searching the phone and Internet records of Americans to gather information on suspected terrorists overseas.

A Washington Post-ABC News poll released late last month found that Americans are divided over whether they support the surveillance programs. But most Americans — 57 percent — still say it's more important for the government to investigate terrorism than to put privacy first.

Lawmakers are divided. Last month, a House proposal that essentially would have made the NSA phone collection program illegal failed in a 217-205 vote. Republican House Speaker John Boehner and Democratic leader Nancy Pelosi were among those who voted to spare the program.

Doug Hattaway, a Washington-based Democratic strategist, said the reluctance by most lawmakers to take sides isn't surprising, considering that most Americans say they want both security and privacy.

Another challenge for surveillance foes is that industry isn't exactly fighting back. Technology and phone companies often say they are prohibited from revealing details about government surveillance requests, but that's only partially true. Federal law prohibits alerting customers when they are surveillance subjects as long as a court order remains in effect. But not all orders last forever.