There is no evidence that these folks are FSers, other than them saying they are FSers.
If they've said in public forums that they're FreeStaters, then there are going to be many who take them as just that, regardless of whether they've ever officially signed up.
Someone protesting overreaching government at the Tea Parties claiming an affinity or membership in the FSP, I'd think that's a good thing. Tax protesters, outlaw manicurists, people filming police stops and in courtrooms... all good. Worst thing someone "mainstream" is likely to think is that the FSP has a few quirky people in membership.
But anytime a story like this... or something like welfare fraud comes out with people who say they're FreeStaters, that's not a good thing for the public perception of the group.