Buying new tires can be pretty intimidating. Depending on the car you drive, you could be paying as much as $200 per tire. That's pretty expensive if you're on a budget, so a lot of folks opt to buy used tires instead. This is ok, as long as you know what to look for and trust the seller.
Unfortunately, unscrupulous dealers can sometimes employ methods like the ones seen in the video below. Although this tire might look like it's brand new and has great tread, it's certainly not safe. This is a real wake-up call.
H/T: Jorski Pappa