LYNN – A proposed bill to protect children against sexual predators lurking on popular social-networking sites has city officials both applauding it and questioning its enforceability.If passed, the bill, which is spearheaded by Norfolk County District Attorney Michael Morrissey, would require level three sex offenders to register their e-mail addresses and online monikers for Facebook, Twitter and other messaging boards with the Sex Offender Registry Board.As a result, unsuspecting children, teenagers and young adults would be safeguarded from their prying eyes. Or would they?”Let’s just be honest here, there is hardly any constituency for sex offenders,” said City Councilor at large Daniel Cahill. “But from what I understand, it’s pretty tough to regulate the Internet, so who is going to police this? It’s great in theory, but will it protect children? Probably not.”Cahill said he also questions whether the offenders would even register their correct e-mail address or name in the first place.”Unless there’s an electronic bracelet on them it’s really difficult to monitor someone’s every waking move unless they’re incarcerated,” he said. “And I’m not at all concerned with inconveniencing the sex offenders one bit by having them do this, but it’s just the practical application of how this will even work.”Lynn Police Capt. Michael Mageary said the proposed bill is worth a try even with the possibility that sex offenders would try and skirt around the issue of registering.”Any tool to help protect kids from predators is good stuff,” Mageary said. “If it does pass, this would give us the opportunity to track them. I don’t know if it will act as a pop-up (when the name or address is online) or if it would use the IP address, we’ll have to see how it is enforced.”City Council President Tim Phelan said he is thrilled with the concept.Phelan said he keeps a watchful eye on his 16-year-old daughter’s site and frequently tells her to be wary of talking to people online who she doesn’t know.”Level 3 sex offenders are the most likely to re-offend and more and more of them do all their predating online,” Phelan said. “They have done horrific things to people and they should have a close eye on them.”Phelan said he recently sat down with his daughter and explained the dangers of online predators and what she shouldn’t be broadcasting on the site.”Parents have to change with the times and protect their kids,” he said. “My daughter is a good kid and a great student, but I told her that nothing is going to be private on Facebook and I had her give me her password.”Monitoring the usage of the site at school is also key, according to School Committee member Donna Coppola.”I don’t think kids even realize it’s happening to them,” she said. “It’s scary, but a lot of these things can be prevented. It’s the obligation of parents and the school system because the police can’t do it all.”If passed, those who fail to register would be slapped with a criminal offense and fines. The bill will be discussed by lawmakers in the coming weeks.