Updated

Over the past decade, Americans have witnessed the rise of social networks and mobile technology that's put the Internet at an arm's reach, day and night — yet a new study has found that people are even more distrustful of the information they find online.

Three-quarters of Internet users find the Web an important source of information, but most people still don't deem the content they see online reliable, according to a report out this week from the University of Southern California's Center for the Digital Future

Such are the deep chasms among Americans' attitudes about the Internet.

In 2010, 15 percent of Internet users said they find only a small portion of online information reliable. That's greater than the 7 percent who were likewise skeptical of the vast majority of information they come across on the Internet.

The mistrust is especially true for social networks. That said, people don't look to social networks for reliability. Rather, they visit the sites to socialize and share photos, updates and videos.

Trust grows when it comes to established media outlets and government websites. In 2010, 79 percent of Internet users said they found content posted on government websites reliable, about the same as in 2003, the first year the center looked at that question.

Jeff Cole, director of the Center for the Digital Future, said Americans tend to be more trusting of government and big media.

"Other countries are better at distinguishing good information from (the) unreliable," he said. In repressive regimes where media is closely tied to the government, citizens grow adept at filtering truth from propaganda.

When it comes to privacy online, Americans are actually more concerned about businesses than the government, the report found. Nearly half of U.S. Internet users said they are worried about companies watching what they do online, compared with 38 percent who said the same for the government.

Looking ahead to the next decade, Cole expects tablet computers and other touch-screen devices to largely replace personal computers and with them, the clunky computer mouse.
The center has surveyed more than 2,000 U.S. households each year since 1999. The latest report is a look back at the past decade of Americans' Internet use. The margin of error is plus or minus 3 percentage points.