In the last months of his presidency, former President Barack Obama focused on pushing forward criminal justice reform. Throughout his eight years in the Oval Office, he also prioritized  “banning the box” on federal job applications and reforming conditions in federal prisons. Given his dedication to criminal justice reform, some have been perplexed by his signing of International Megan’s Law, which may violate sex offenders’ constitutional rights.

President Obama signed the bill into law in February 2016 and it went into effect in 2017 under President Trump. The law requires registered sex offenders convicted of crimes against minors to carry a special passport that states their conviction when traveling abroad. Further, a sex offender must inform the Department of Homeland Security of any international travel plans in advance, after which the U.S. government will inform the country to which the individual is traveling that a “covered sex offender”—one convicted of a sexual offense against a minor—will be traveling there. The law also requests that other countries inform the U.S. if a known sex offender is seeking to cross their borders.

International Megan’s Law is an expansion of the federal Megan’s Law. Signed in 1996, it became the model for individual states to adopt. One of the motivations behind the expansion was to eradicate the sexual exploitation of children, as some predators travel abroad to exploit children in other countries. As the law indicates, child pornography and child sex tourism are international phenomena that law enforcement have struggled to adequately address. A 2010 report by the Government Accountability Office found that the federal government had no legal means of monitoring or denying passports to registered sex offenders, except those convicted of sex tourism.

The International Megan’s Law would seem to provide a solution to the problem because some American sex offenders will now be tracked and readily identifiable outside the country. However, several civil rights groups and commentators criticized the bill before and after it became law. Some likened the special passports to a scarlet letter or even the “yellow star” under the Nuremberg Race Laws. Others questioned whether the law would even combat child sex trafficking or exploitation. In early January 2018, the Alliance for Constitutional Sex Offense Laws and two California sex offenders filed a lawsuit alleging the State Department violated public comment procedures and threatened not to issue passports to some offenders.

As these challenges indicate, tracking sex offenders as they travel abroad poses serious constitutional concerns. One concern is that the law is both overbroad and too narrow, undermining its effectiveness.

The law has the potential to affect many people: a “covered sex offender” under the law means anyone convicted of an offense against a minor, which may be more than 500,000 people, not all of whom are violent predators. One criticism of the sex offender registry is that low-risk—or no-risk—one-time offenders who were convicted in special circumstances should be excluded from the registry. Similarly, this law would affect a sixteen-year-old convicted of statutory rape for having sex with his fifteen-year-old girlfriend when the age of consent in the state is sixteen because, according to International Megan’s Law, a minor is anyone under the age of eighteen. In one case, a nineteen-year-old who had been flirting with a girl who said she was seventeen, but who was actually fourteen, was also placed on the registry.

International Megan’s Law affects both of these types of individuals, despite each having a very low risk of reoffending. On the other end, the law excludes sex offenders who may be dangerous and at a high risk to reoffend, but who did not commit an offense against a minor. A prior offense against a minor is not necessarily a prerequisite for exploiting a child abroad. In general, data suggest that sex offenders have among the lowest same-crime recidivism rates. These discrepancies illustrate that the law may be more effective if it considered specific, aggravating factors in a sexual offense, such as interstate travel to have sex with a minor or a particularly brutal assault.

As it stands, some have argued, International Megan’s law is both over- and under-inclusive. It remains to be seen whether the law will effectively address child sex tourism if it does not take into account the nuances of sexual assault convictions.