Some 700,000 Swedes currently actively seek to hide their identity online by making use of anonymizer services, according to the survey by the Cybernorms project at Lund University.
The survey shows that around 200,000 Swedes aged 15-25-years-old habitually surf anonymously, making use of proxy services such as Relakks, Ipredator and Mullvad - this equates to 15 percent of the age group.
The researchers conclude that as internet usage and file-sharing is most common among younger Swedes, then the proportion of older users surfing anonymously is likely to be lower.
"We can't say for certain for other age groups, but a rough estimate, based on the recognition that other age groups don't share files illegally to the same extent, is that around 700,000 Swedes are currently paying for a service to conceal their identity on the internet," said Måns Svensson, PhD in sociology of law and the survey's project manager.
The figures came as a surprise however as a prior survey on the issue by the Swedish Post and Telecom Authority (PTS) showed little change since 2009.
The European Court of Justice furthermore indicated recently that the controversial anti-file sharing IPRED law (named after the EU intellectual property rights directive) could be brought into force in Sweden.
The law allows for copyright holder organizations to obtain the identity of suspected file sharers from internet service providers, suggesting that the demand for anonymization services will increase.
"If the European Court's opinion leads to an intensified hunt for file-sharers, the indication is that the use of these types of anonymity services will expand even faster," Smith said.
The Lund University researchers concluded that file-sharing is the single most important factor in the growth in demand for online anonymity, but it has also been found to be expanding among other internet users.
Danny Aerts, president of the .se foundation which administers Swedish network addresses, estimates that the increasing level of surveillance on the internet is instrumental in the increasing popularity of anonymizing services.
"As surveillance increases, both from the government and from private actors such as Facebook and Google, so does demand (for anonymization services)," Aerts said.
"But I think it's good that anonymization services are available. Take the Arab Spring for example; then everyone in Sweden considers it a good idea that anonymity is possible. And it would be strange if that did not also apply at home."