"Although many checkers mentioned that they had not heard of anyone being prosecuted for possession of test kits, many were more directly affected by party promoter and venue owner reluctance to allow their services due to fear of fines or even prison sentences. Checkers affiliated with formal drug checking organizations in particular expressed concern over potential legal barriers associated with drug checking at festivals or other events. The main concern cited by many formal checkers is the “RAVE Act” (the “Reducing Americans’ Vulnerability to Ecstasy Act”). Although this bill in 2002 was never passed, it was reintroduced in US Congress the following year as the Illicit Drug Anti-Proliferation Act which made it illegal to knowingly lease, rent, or use a space for the purpose of distributing or using controlled substances. In response to this Act, party promoters and venue owners fear they would be prosecuted if their venue could be deemed a place where drug consumption was “allowed”. According to this Act, property owners or promoters could be fined up to $250,000 and face up to 20 years in prison if their parties were deemed places where illegal drug use was taking place.

"Checkers commonly cited this law (which they still refer to as the “RAVE Act”) as a major barrier to their harm reduction services as such organizations are often not given permission by party promoters or venue owners, because permitting them to operate on-site could be seen as encouraging or allowing drug use. There were also instances mentioned in which drug checking organizations acquire initial approval to set up a booth at a festival, and then the organization is denied access the day of the festival due to fear of legal liability."

Source

Palamar, J. J., Acosta, P., Sutherland, R., Shedlin, M. G., & Barratt, M. J. (2019). Adulterants and altruism: A qualitative investigation of "drug checkers" in North America. The International journal on drug policy, 74, 160–169. doi.org/10.1016/j.drugpo.2019.09.017