i have made my first ever contribution to urban dictionary: "feature abuse"
using a feature of something (device, website, etc.) for a purpose it wasn't meant for, to the point where it irritates other people.
eg: Having conversations in the comments section of someone's facebook photo is classic feature abuse.
btw, the coinage (yes, that's a real word that i didn't just make up) was inspired by a conversation on my facebook status.