Legislators in Connecticut are expressing concern over the low number of gun owners who registered now banned semi-automatic rifles, prompting some groups to push for confiscating previously legal firearms from as many as 100,000 residents.

According to recent reports, only about 50,000 so-called "assault weapons" were registered with Connecticut law enforcement to comply with new laws enacted shortly after the Sandy Hook elementary school shooting. Some indicate that's about 15 percent of the number of now banned semi-automatic rifles in the state.

"I honestly thought from my own standpoint that the vast majority would register," state Sen. Tony Guglielmo told the Hartford Courant. "If you pass laws that people have no respect for and they don't follow them, then you have a real problem."

Earlier in the year, Connecticut Democratic governor Dannel Malloy contemplated granting amnesty for gun owners who missed the Jan. 1 deadline to register their rifles, but anti-gun groups in the state pushed back, saying any amnesty must come through legislation.

Gun advocates are worried that as many as 100,000 otherwise law-abiding Connecticut residents are now felons and are exercising a kind of civil disobedience by refusing to register their previously legal rifles and magazines. The state's top advisor to the governor on gun laws has said that his office might track down unregistered owners by comparing lists of people who purchased so-called "assault rifles" in the past with the names of people who registered their rifles by the Jan. 1 deadline.

"It wouldn't surprise me if they did that," said Scott Wilson, president of the Connecticut Citizens Defense League, which has been fighting the rifle ban in court. "I'm extremely concerned what might happen if they went door-to-door to confiscate the rifles from people who didn't know about the law or were unsure if their rifle was subject to it."

Wilson stopped short of suggesting there might be a violent confrontation, but he did worry that anyone caught in the gun grab would be "treated like a criminal" and subject to prison and fines.

"I wish the state would back off and leave gun owners alone," Wilson said in an interview, adding if a Connecticut gun owner does have an unregistered semi-automatic rifle, "I'd make sure to have the number of a good 2nd Amendment attorney on hand."