A January 2006 Washington Post/ABC poll--which was released in the wake of President George W. Bush's "terrorist surveillance program"--found that 51 percent of Americans believed it was appropriate for the NSA to investigate suspected terrorists by "secretly listening in on telephone calls and reading e-mails between some people in the United States and other countries, without first getting court approval to do so."
Pew highlights partisan shifts on the issue between 2006 and 2013, which may be attributed to a change of party in the White House. In 2006, 75 percent of Republicans and 37 percent of Democrats thought it was acceptable to monitor phone records in the name of national security. Today, 52 percent of Republicans and 64 percent of Democrats find it acceptable.
The most recent numbers change slightly when broken down by age. The recent Pew poll found that 68 percent of Americans over 65 believe that it is more important to investigate terrorism than to protect personal privacy, while 51 percent of 18 to 29-year olds believe that investigating terrorism is a more important priority.
The public is slightly more divided over whether the government should be tracking emails. While 56 percent of Americans say they are okay with the NSA tracking phone records, only 45 percent believe the government should be monitoring their emails. Forty-seven percent said the government should not track emails at all.
The survey polled 1,004 adults living in the U.S, about half on landlines and half on cell phones. The poll has a 3.7 percent margin of error.