According to an August 2009 Economist article, the Georgia Sex Offender Registration Review Board sampled its registry and concluded that 65% of folks on the list "posed little threat." 30% were "potentially threatening," and 5% were "clearly dangerous."
Social media researcher danah boyd speaks to the Gov 2.0 Expo about sex offender registries as an example of how government transparency is not enough: we can release lots of data, but we must include context and help people develop media literacy so they can properly interpret that data.
Boyd provides a draft of the presentation text. Among the important passages:
The problem with the registry is not its intention. Of course we want to give people the tools to protect their children. The problem is also not simply one of transparency. In fact, the transparency of these lists allows us to call into question how our laws are enforced. The problems that stem from the registry stem from the fact that people misinterpret what the data means. When the list of registered sex offenders is made available out of context, it's easy for people to misinterpret what they see. And boy do they ever. In most of your minds, a registered sex offender is automatically Evil Incarnate. So when someone has that Scarlett Letter attached to their chests, they are immediately judged without the circumstances and situation being understood. Transparency may allow us to see who's registered, but for this information to be used effectively, it needs to be communicated in context. In short, we need people to not just have access to the data, but have access to the context surrounding the data [danah boyd, "Transparency Is Not Enough," Gov 2.0 Expo, 2010.05.26].
Boyd also notes that she has done research that adds some important context to the statistics about the danger of sexual solicitations minors face on the Internet:
Consider the statistic from 2006 that 1 in 7 minors are sexually solicited online. This statistic flew around the press and was employed by Attorneys General across the U.S. to argue that the Internet is dangerous for children. This statistic was from a highly reputable source - the Crimes Against Children Research Center. The problem is not the statistic; it is accurate. It's what it implies without further clarification. Most people interpret this statistic as suggesting that 1 in 7 minors are sexually solicited by older sketchy adults seeking to meet minors offline for sex. Yet, over 90% of sexual solicitations are from other minors or young adults and 69% of solicitations involve no attempt at offline contact. Finally, the researchers used the term solicitation to refer to any communication of a sexual nature, including sexual harassment and flirtation [boyd, 2010].
When boyd publicized this research, a state attorney general called and told her to "go find different data." When she stuck by her research, that AG proceeded to trash her in the press.
The lesson here is not that we can't trust statistics or that we shouldn't look to data. Quite the opposite: the lesson here is that when we get statistics and data, we need to get even more information to put the data in proper context.