Buying tickets with RyanAir is stressful due to these kind of practices. They're less aggressive than in the past, when I wouldn't even continue because I just had zero trust in the company, but they're still sly.

A sneaky one I saw recently is something like:

[ ] Subscribe to newsletter about our services by unchecking this box.

(It doesn't matter whether the box is initially checked or not, the user will be tricked into the desired behavior.)

I don't remember the exact phrasing, and it was much more shrewd than my own, but it relied on a boolean flipping of the value of the checkbox towards the end of the field label. Any user seeding the start of the sentence will leave it in its current state.