Anna Gingras - who is a travel writer - says the most rude thing someone can do on a plane is recline their seat.
Gingras explained in Outside Magazine: "There's one thing I hate about flying, and it's not the overpriced tickets or the baby crying three rows ahead of me in economy class."
"It's the people who recline their seats with total disregard for the person behind them."
The writer went on to explain people are aware they "suck" when they recline their seat, but do it anyway because they're "ignorant".
She warned: "But if you're reclining your seat on a two-hour, midday puddle jump, I hope you miss your connection and get stuck at LaGuardia Airport without even an $8 coffee to comfort you.
"The thing is, you know you suck when you hit that recline button, but just in case you truly are ignorant, hear this: your actions have direct consequences for the people around you - any space you take is taken from someone else."