Americans are worried about the privacy of their online information, and have little confidence the government will keep that data secure, a poll showed Wednesday.

The Pew Research Center survey highlighted ongoing fears about online privacy, with concerns about how data is safeguarded by the government, credit card companies, social networks, search engines and others.

Just six percent of adults surveyed say they were "very confident" that government agencies can keep their records private and secure, with another 25 percent saying they were "somewhat confident."

The confidence was at the same level for landline telephone companies, and marginally higher for credit card companies -- with nine percent "very confident" and 29 percent "somewhat confident" about the security of their data.

This was the third Pew survey on privacy since revelations by former National Security Agency contractor Edward Snowden stunned many Americans and angered US allies.

An overwhelming majority of 93 percent said being in control of who can get information about them is important to them, and a similar number said they want to decide with whom they share data.

But three out of four said they had little confidence about the security of records of their online activity tracked by advertisers, and two-thirds expressed similar concerns about social networks and search engines.

"In the almost two years that have passed since the initial Snowden revelations, the public has been awash in news stories detailing security breaches at major retailers, health insurance companies and financial institutions," said Pew researcher Mary Madden.

"These events and the doubts they have inspired have contributed to a cloud of personal 'data insecurity' that now looms over many Americans' daily decisions and activities. Many find these developments deeply troubling and want limits put in place."

A number of those surveyed said they had taken extra steps to protect privacy or private data, although few took drastic measures.

Some 59 percent said they had cleared browser histories or "cookies," while 57 percent refused to provide information about themselves that wasn't relevant to a transaction.

- Encryption elusive -

One out of four used a temporary username or email address or gave inaccurate or misleading information about themselves to protect their privacy, the survey found.

But only 10 percent said they encrypted phone calls, text messages or email and nine percent used a service that allows them to browse the Web anonymously.

More than half -- 55 percent -- of those surveyed support the idea of online anonymity for certain activities, 16 percent said this should not be allowed and 27 percent were unsure.

The poll comes amid a debate in Congress over the extension of a section of the Patriot Act which has been used to justify vast data collection efforts by the government.

The government and the tech sector meanwhile remain at odds over the use of encrypted devices which could prevent law enforcement from gaining access to communications of suspects in criminal or terrorist investigations even with a court order.

In the latest survey, 88 percent said they did not want to be monitored without their approval.

Sixty-five percent said there were no adequate limits on "what telephone and Internet data the government can collect" as part of anti-terrorism efforts.

The survey showed those who are more aware of government surveillance efforts are more likely to believe there are not adequate safeguards: 74 percent of those who have heard "a lot" about the programs say that there are not adequate limits, compared with 62 percent who have heard only "a little" about the monitoring.

The report is based on an online panel of 498 adults between August 5 and September 2 with a margin of error estimated at 5.6 percentage points and a second survey of 461 people from January 27 to February 16 with a 5.6 point margin of error.