The use of federal funds for needle-exchange programmes was banned in 1988, but this ban was overturned in 2009. The use of federal funds for syringes, needles and items whose only purpose is to prepare drugs for illegal drug injection such as cookers is prohibited. The use of funds are allowed in some situations with the exception of these prohibited purposes. In the time before the federal funding ban was re-instated in 2011, at least three programmes were able to obtain federal funds and two thirds reported planning to pursue such funding. A 1997 study estimated 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.