Right now it is when people piss about with married and maiden names on Facebook, when there is an actual setting for it.
Like this - all examples I've seen recently (all spacing exactly as typed to fit in the firstname and lastname boxes):
SamWasSmith NowJones
Jane Doe(wasBloggs)
Mary "Brown" Black.
Don't even get me started on joint accounts:
ClaireAndMike Baker
Sue'n'Dave Butcher
JeanAnd BarryCook