Two experiences come to mind;

1. FA trying to find space for a Y passenger's bag ask me in 3A if I would mind placing
it under 2A, taking my foot space. Errrr..NO.

2. In 2F female passenger in 1F places a large bag under her seat taking up half my
foot space. I ask her to move it, tells me "well I need to access it". Fair enough, I
spent the flight using her Louis Vuitton as a shoe cleaner and a foot rest