Social Networks not for Antisocials

Sexual offense is an antisocial behavior. Many cases have already come up abroad where these social networks in the internet have been used for crimes to be committed. Now New York is trying to pass a bill against internet access of sex offenders. They have tried to do so in the past but it wasn't approved. They wish to ban sex offenders from social networks.

1. The bill would make it a parole condition for sex offenders with child victims or a history of using the Internet to commit sex crimes to register their screen names and other identifiers for instant messaging, e-mail, and other Internet communication.
2.Those offenders would not be allowed to access social networking sites, view pornography, or communicate with anyone to promote sex relations with minors. It would also prohibit Internet communications with people under age 18, in most cases.
3.The bill would allow the Division of Criminal Justice Services to release offenders' information to networking sites and some other Internet services to help private companies prevent offenders from joining.

It seems that the internet has become a right of the users that can be trespassed and violated. There may be protests on the constitutional ramifications on freedom of expression, freedom of association and privacy vs. state interest. Isn't this already penal in nature?

Sources:
http://www.webpronews.com/topnews/2008/01/29/ny-lawmakers-propose-bill-to-make-social-networks-safer
http://www.informationweek.com/news/showArticle.jhtml?articleID=206504177