Was sat in an emergency exit row recently (Southwest Airlines 737-800), next to the window.
2 pax boarded and sat alongside, one lowered the seatback tray table to use as a resting place for his rucksack, then spread in-flight magazine over it to complete crossword.
Then pushback and taxi, completely ignored safety brief, completely ignored cabin crew briefing to stow luggage. It took a prod of the "call attendant" button to draw the attention of cabin crew to the blocked exit row (if my window wouldn't open when I wanted it to, then I was moving left and not prepared to battle a tray table and rucksack for space).