Just 26 days after the implementation of I-594, opponents filed a federal lawsuit challenging a provision of the state's newly expanded gun law. "I-594 is also so vague that a person of ordinary intelligence cannot understand its scope, which renders it subject to arbitrary enforcement," reads the complaint. The suit is targeted specifically at I-594’s restriction of the noncommercial transfer of firearms.

"The gun lobby lost overwhelmingly at the ballot box, so now they're taking the people of Washington to court," Geoffrey Potter, communications director for the Washington Alliance for Gun Responsibility, wrote in an e-mail statement. "Despite clear evidence that 594 is working, the gun lobby is shamelessly attempting to change our state's law to make it easier for criminals to get guns. We look forward to a vigorous defense by the state of Washington against this frivolous and meritless suit."

Named as defendants in the suit are Washington State Attorney General Bob Ferguson and Washington State Patrol Chief John Batiste. "As Attorney General, I look forward to vigorously defending the will of the voters and upholding Initiative 594," Ferguson wrote similarly in a statement e-mailed to the Associated Press.

Represented by Corr Cronin, the Bellevue-based Second Amendment Foundation and other plaintiffs filed the suit December 30 in district court in Tacoma. I-594 requires background checks for all gun sales in the state, including gun shows and online sales, but it also requires a check for many transfers. And it's that word "transfer" that the lawsuit hinges on. It offers examples such as "family members’ common use of a firearm stored in the family’s gun-safe, where no delivery takes place to another person," and "the intended delivery of a firearm to a storage facility, such as a safety deposit box," among others.

I-594 states that "background checks would not be required for gifts between immediate family members or for antiques," and carries other provisions for hunting and situations involving personal safety, and it defines "transfer" as "the intended delivery of a firearm to another person without consideration of payment or promise of payment including, but not limited to, gifts and loans."

“We’re not trying to stop background checks,” SAF founder and executive vice president Alan Gottlieb said in a prepared statement. “We’re taking action against a poorly-written and unconstitutionally vague measure that criminalizes activities that are perfectly legal anywhere else in the country, thus striking at the very heart of a constitutionally-protected, fundamental civil right."