Increasingly, nonprofits in the U.S. are using their websites to encourage community engagement and civic participation, a says.

While regulations dictate much of what nonprofits may do in the advocacy field, many are finding legal to use the Internet to boost civic engagement, says the study by David Suarez, assistant professor of policy, planning and development at the University of Southern California.

Leaders in the area are environmental groups, human-rights groups and "policy entrepreneurs," organizations that are involved in the making of policy through the legislative process.

"Websites provide a novel opportunity for nonprofits to scale their social impact and expand their civic purpose," Suarez says in a statement.

Financial resources appear to have little effect on whether or not a nonprofit engages in online advocacy, the study says, but larger organizations are more likely to be involved than smaller ones.

Policy entrepreneurs and rights and environmental groups are more likely to be involved in online advocacy than other groups and are more likely to address advocacy on their websites.