vaxvms
It’s a difficult situation because there are some [relatively] honest limited-coverage plans on the market too.
These actually have some government blessing to bypass the otherwise strict rules of the Affordable Care Act (ACA).
Such policies are sometimes called Short-Term, Limited-Duration Insurance (STLDI).
https://www.cms.gov/newsroom/fact-sheets/short-term-limited-duration-insurance-and-independent-noncoordinated-excepted-benefits-coverage-cms
(Federal website)
It can be very hard for some people to differentiate between [total scam policies] and the [STLDI policies], especially when people have limited sophistication.
But as you say—insistence that people have to sign up NOW! NOW! is a good tipoff.
There are also some co-op type coverages from various church groups which exist in a Wild West unregulated environment. Again, SOME are reasonably legitimate, while OTHERS are scams.
Unfortunately in this country, too many people are desperate for any type of health coverage (the exchange/ACA plans being so expensive) which is WHY scams can flourish.