WASHINGTON (Reuters) - A majority of Americans are unwilling to share their personal emails, text messages, phone calls and records of online activity with U.S. counter-terrorism investigators - even to help foil terror plots, according to a Reuters/Ipsos opinion poll released on Tuesday.

FILE PHOTO: A businessman sits on a bench looking over his mobile phone in downtown San Francisco, California February 4, 2016. REUTERS/Mike Blake

The poll showed Americans were more reluctant to share personal information than when the poll last asked the question four years ago.

For instance, 75 percent of adults said they would not let investigators tap into their Internet activity to help the U.S. combat domestic terrorism. That’s up from 67 percent who answered the same way in June 2013.

But Americans were more evenly divided when asked whether the government is conducting too much surveillance, showing that while they are deeply concerned about their own privacy there remains a pool of support for U.S. spying programs that can sweep up personal information.

Congress is due to address questions about surveillance later this year when it opens debate over whether to limit the government’s ability to conduct warrantless searches of American data.

According to the March 11-20 survey, 32 percent said intelligence agencies such as the FBI and National Security Agency are conducting “as much surveillance as is necessary” and 7 percent said they wanted more surveillance. Another 37 percent of adults said agencies are “conducting too much surveillance on American citizens.” The remaining 24 percent said they did not know.

For a graphic of the poll results, click here: tmsnrt.rs/2nTXXRv

Later this year Congress must decide whether to reauthorize a key section of the Foreign Intelligence Surveillance Act that expires on December 31. The section allows U.S. intelligence agencies to collect vast amounts of communications from foreigners, but often incidentally scoops up the communications of Americans.

Democrats and Republicans in Congress have expressed interest in limiting warrantless searches of such U.S. data, but a White House official told Reuters last month the Trump administration did not support changes.

The Reuters/Ipsos poll was conducted online in English in all 50 states. It surveyed 3,307 people, including 1,209 Republicans and 1,355 Democrats. The poll has a credibility interval, a measure of accuracy, of 2 percentage points for the entire group and 3 percentage points each for the Republicans and Democrats.

The entire poll can be found here. [tmsnrt.rs/2mWiLZm]