When the second Youtube preroll ad cuts off the first one...

My favourite development in this regard is the lying timers on those ads. More than one streaming app I've caught resetting the overall timer on every ad. So it will say that there's 90s of ads, play through a 15s ad counting down to 75s, and as soon as the next ad plays, the timer resets to 90s again. Eventually after a few minutes of ads something must realize that it's actually been more than 90s, and just cuts off the current ad in the middle. Or even more fun is when it says you can skip in X seconds, but every ad it plays is Y seconds, where Y < X, and the skip timer resets with every ad. Looking at you Youtube.