I know nothing about stacking elk, though I'm sure it's easier if you sedate them first. But yeah, common sense and a healthy dose of skepticism seems like the way to go!
Or even better: Be the "good guy" by giving your cat a happy, healthy, secure, and longer life by keeping them indoors. People hate to be told what to do, and some cats love it outside, but guess what? My dog would love to eat 10lbs of chocolate. We have to look out for their best interests. This obviously doesn't mean don't ever take them outside leashed or supervised, but the fact remains: indoor cats have a better, less stressful life, and don't decimate local bird populations...
I know nothing about stacking elk, though I'm sure it's easier if you sedate them first. But yeah, common sense and a healthy dose of skepticism seems like the way to go!