The Catholic bishop of Lincoln, Nebraska, is excommunicating members of his diocese who belong to organizations he says oppose church teaching.

In an official edict March 22, Fabian Bruskewitz, 60, named a dozen groups Catholics are forbidden to join. "Membership in these organizations or groups is always perilous to the Catholic faith and most often is totally incompatible with the Catholic faith," he said.

The groups include Planned Parenthood, the Hemlock Society, Catholics for a Free Choice, five Masonic groups, and Call to Action, a Catholic organization that opposes church teaching on birth control, female ordination, and married clergy.

"We're not keeping lists," says Monsignor Timothy Thorburn, chancellor of the 83,900-member Lincoln diocese. "We don't know who are members of these organizations. The onus is on the members of these organizations."

Thorburn says the diocese assumes those receiving Communion since April 15 are not members of the forbidden groups. However, members who remain in the named organizations will be excommunicated May 15.

Thorburn says 95 percent of those who have contacted the diocese have been supportive of the bishop's actions.

But University of Notre Dame professor Jay Dolan describes Bruskewitz as a bishop who wants "to stifle any discussion or debate." He calls the edict "a throwback to 200 years ago."