that while the funding ban was in effect, it "may have led to HIV infection among thousands of IDUs, their sexual partners, and their children." US NEPs continue to be funded through a mixture of state and local government funds, supplemented by private donations. The funding ban was effectively lifted for every aspect of the exchanges except the needles themselves in the omnibus spending bill passed in December 2015 and signed by President Obama. This change was first suggested by Kentucky Republicans Hal Rogers and Mitch McConnell, according to their spokespeople. Legal aspects Many states criminalized needle possession without a prescription, arresting people as they left underground needle exchange efforts. In some jurisdictions, such as New York, needle exchange activists challenged the laws in court, with judges ruling that their actions were justified by a "necessity defense" which permits breaking of a law to prevent an imminent harm. In other jurisdictions where syringe possession without a prescription remained illegal, physician-based prescription programmes have shown promise. Epidemiological research demonstrating that syringe access programmes are both effective and cost-effective helped to change state and local NEP-operation laws, as well as the status of syringe possession more broadly. For example, between 1989 and 1992, three exchanges in New York City tagged syringes to help demonstrate rates of return prior to the legalization of the approach. By 2012, legal syringe exchange programmes existed in at least 35 states. In some settings, syringe possession and purchase is decriminalized, while in others, authorized NEP clients are exempt from certain drug paraphernalia laws. However, despite the legal changes, gaps between the formal law and environment mean that many programmes continue to face law enforcement interference and covert programmes continue to exist within the U.S. Colorado allows covert syringe exchange programmes to operate. Current Colorado laws leave room for interpretation over the requirement of a prescription to purchase syringes. Based on such laws, the majority of pharmacies do not sell syringes without a prescription and police arrest people who possess syringes without a prescription. Boulder County health department reports between January 2012 and March 2012, the group received over 45,000 dirty needles and distributed around 45,200 sterile syringes. As of 2017, NSPs are illegal in 15 states. NSPs are prohibited by local regulations in cities in Orange County, California, even though it is not disallowed by state law in California. Law enforcement Conflict with law enforcement Removal of