I never said anything to infer they are exempt, nor do I believe they are. But needing to comply such as providing accommodations such as accessibility, communication aids, etc as all gov agencies must do is not the same thing as determining what can be questioned when investigating a crime. This is the area that would need court interpretation.
So what.. in this scenario the police are not investigating or trying to enforce the ADA.
The ADA protects people from discrimination and being denied accommodations. It does not grant them, or their service animals, some blanket immunity from scrutiny. A police officer investigating a suspected crime is not interfering with the person receiving accommodation or altering what the public accommodation is doing. The grey area is how one determines probable cause given the lack of registration and the grey area with the ADA. Hence why ultimately a court will have to set the precedent.
The point was there is no federal standard to define who should get placards, so the federal vs state variation in definition is interesting. It's interesting how someone hasn't challenged the standard for requiring a placard - which could be argued is like a Scarlet Letter and a unnecessary burden if the DoJ argues that documentation for other disabilities would be discrimination, etc. Gaining access to such accommodation requires registration in a state regulated and operated program. The ADA defines 'accessible' parking, yet acknowledges and lets states limit access to them, even if the limitation would exclude someone who is disabled by definition of the ADA. So the states limit and force registration and proof to gain access to an accommodation dictated under the ADA. The DoJ acknowledges and allows states to define qualifications and enforcements that in effect limit access to an accommodation mandated by the ADA. Kind of like.. making it a crime to fake a service animal.
Which is exactly why the practice is to not check documentation - you can't use it as a defendable point to deny accommodation. So what does checking gain you? Nothing.. in fact it opens you to scrutiny in discriminating by requiring additional burdens. I don't see such a policy lasting and it goes against the DoJ's interpretations and findings. It would only take one activist to intentionally go in without documentation, be denied, and take them to court and win easily. It sets SixFlags up to fail and goes directly against DoJ interpretations. Doomed to fail. Disney's registration program already invites enough scrutiny... and it doesn't even risk denying access. Sixflag's idea is just begging for punishment.