The only worry topping online privacy was getting in a car accident; which was at 27 percent. YouGov conducted a similar survey in Japan and Russia and the results were similar. Online privacy was among the top four concerns in all three countries.

Despite the concerns about online privacy, only 61 percent of Americans say they use safe passwords. Only 47 percent regularly delete browsing history and a mere 15 percent only use software and websites that do not collect personal information.

"It is interesting to note the gap between what people say concerns them online and what they do in practice to protect themselves. We often see that it is human nature to fear traffic accidents but not wear a seatbelt or helmet, or dread bankruptcy but continue spending, and it very much seems like it is the same for online behavior," saidChristen Krogh, chief development officer at Opera Software, in a statement.

The majority -- 35 percent -- of respondents were concerned about the government watching them, whereas 16 percent said they did not worry about anyone having too much insight into their online behavior. People said they thought the desktop computer is the safest machine to access the internet with, while the mobile phone is the least safe.

In the U.S. and Russia, people pinned the responsibility for better online privacy and safety on themselves. While in Japan, respondents said it was the responsibility of the web site operator.