I do my part by using FOSS. My only sin is using Windows at work because it's what the Engineers use.
My cellphone OS and web browser are FOSS.
My personal and side project server is FOSS.
I even used GIMP for 10+ years before finally giving adobe 10$ so I could knock out a flyer real quick.
I think we all know who the devil in the room is. FOSS fans know who the sinners are.