<P> Restrictions may effectively cover entire cities, leaving small "pockets" of allowed places of residency . Residency restrictions in California in 2006 covered more than 97% of rental housing area in San Diego County . In an attempt to banish registrants from living in communities, localities have built small "pocket parks" to drive registrants out of the area . In 2007, journalists reported that registered sex offenders were living under the Julia Tuttle Causeway in Miami, Florida because the state laws and Miami - Dade County ordinances banned them from living elsewhere . Encampment of 140 registrants is known as Julia Tuttle Causeway sex offender colony . The colony generated international coverage and criticism around the country . The colony was disbanded in 2010 when the city found acceptable housing in the area for the registrants, but reports five years later indicated that some registrants were still living on streets or alongside railroad tracks . As of 2013 Suffolk County, New York, was faced with a situation where 40 sex offenders were living in two cramped trailers, which were regularly moved between isolated locations around the county by the officials, due to local living restrictions . </P> <P> Evidence to support the effectiveness of public sex offender registries is limited and mixed . Majority of research results do not find statistically significant shift in sexual offense trends following the implementation of sex offender registration and notification (SORN) regimes . A few studies indicate that sexual recidivism may have been lowered by SORN policies, while a few have found statistically significant increase in sex crimes following SORN implementation . According to the Office of Justice Programs' SMART Office, sex offender registration and notification requirements arguably have been implemented in the absence of empirical evidence regarding their effectiveness . </P> <P> According to SMART Office, there is no empirical support for the effectiveness of residence restrictions . In fact, a number of negative unintended consequences have been empirically identified that may aggravate rather than mitigate offender risk . </P> <P> According to a 2007 study, the majority of the general public perceives sex offender recidivism to be very high and views offenders as a homogeneous group regarding that risk . Consequently, the study found that a majority of the public endorses broad community notification and related policies . Proponents of the public registries and residency restrictions believe them to be useful tools to protect themselves and their children from sexual victimization . </P>

Do all states require sex offenders to register