In June, the U.S. Supreme Court struck down longstanding precedent by ruling that public sector unions could not force workers to pay dues if those same workers decline to join the union.

The ruling significantly reshapes the role that public sector unions play in American politics, so it's pretty difficult to imagine that there were any labor unions not watching the case. Yet months later, some unions seem not to have gotten the message.

Take the Service Employees International Union (SEIU), Local 521, a San Jose–based group representing some 40,000 workers in California's Central Valley. It has exclusive collective bargaining rights for workers in the Santa Clara Valley Transportation Authority (SCTA). Like most unions in the pre-Janus days, its contract requires SCVTA employees to pay dues even if they do not choose to join the union, though non-members pay a lower cost "agency fee" instead of full dues.

Those "agency fee" payments were the centerpiece of the Supreme Court's ruling in Janus v. American Federation of State, County and Municipal Employees. The court held that unions can no longer collect those fees from non-members.

"Public employees are forced to subsi­dize a union, even if they choose not to join and strongly object to the positions the union takes in collective bar­gaining and related activities," Justice Samuel Alito wrote for the majority. "We conclude that this arrangement violates the free speech rights of nonmem­bers by compelling them to subsidize private speech on matters of substantial public concern."

Yet for some reason, SEIU Local 521 is still collecting agency fees from SCVTA employees. William Hough, for example, has worked at the SCVTA since 2005 but refrained from joining the union. Now he's the lead plaintiff in a class action suit seeking to stop the union from collecting those fees without nonmembers' consent. He also wants a refund of all agency fees previously collected.

Those refunds could cost the union millions of dollars, says Patrick Semmens, vice president of the National Right to Work Legal Defense Foundation, which is representing Hough and had previously argued on Janus' behalf.

"The Supreme Court finally upheld public sector workers' First Amendment right to choose whether or not to support a union without the threat of being fired," Semmens said in a statement. "Further, the High Court made is clear that fees cannot be collected without a clear waiver of First Amendment rights, something the SEIU never gave Mr. Hough and his colleagues."

California state law allows for the collection of mandatory union dues and agency fees, but the new suit argues that Janus makes those state-level laws unconstitutional.

Meanwhile, unions in Oregon and Massachusetts have recently received cease-and-desist letters from attorneys at the Liberty Justice Center, another law firm involved in the Janus case, threatening lawsuits if the unions do not stop deducting fees from paychecks. In both states, unions have continued deducting the fees because those workers consented to joining the union. But the Liberty Justice Center says that's a misinterpretation of the Supreme Court's ruling, which said workers must "clearly and affirmatively" consent to making those payments.

"Any previous authorizations for the deduction of dues or fees that employees made before the Janus decision were based on a choice the Supreme Court has declared unconstitutional: become a member and pay dues, or pay fees to a union as a nonmember," the group's cease-and-desist letters read, in part. "Any 'consent' based upon that unconstitutional choice was made under duress, not freely given, and is invalid."

And in Washington state, six workers filed a lawsuit last month saying they tried to exit the Washington Federation of State Employees after the Janus ruling but were told that they had to wait until an "escape period" that lasts just 10 days and won't come around again until next year.

The Washington State Attorney General's office claims the Janus ruling only affects the payment of agency dues by nonmembers. But that ignores union members who would like to become nonmembers to avoid paying dues. And surely the First Amendment should apply year-round.

"I just want what's right and fair, and the way the union has treated me since the Janus decision is not right, nor fair," Mike Stone, one of the six plaintiffs, tells Fox News. "I don't want my money being used to support an organization I disagree with."