Frequently Asked Questions About Gun Industry Immunity May 4, 2021, 9:01 am Download the PDF here. This fact sheet will be periodically updated to account for new policy developments. It was last updated on May 4, 2021. Click What is the Protection of Lawful Commerce in Arms Act? The Protection of Lawful Commerce in Arms Act (PLCAA) was enacted in 2005 following extensive lobbying by the gun industry to shield gun manufacturers and dealers from civil litigation. 1 The effort to enact this law was a reaction to numerous lawsuits in the early 1990s filed on behalf of more than 40 cities; these lawsuits advanced a novel legal argument alleging that gun manufacturers created a public nuisance through sales practices that enabled firearms to be sold illegally in secondary markets and to be illegally trafficked, after which they ended up being used to commit violent crimes.