Hey - it's not because 'Phoebe' is in itself offensive, but that the 'h-o-e-' string of letters means it didn't pass through the automatic chat filter we have in-game - rather than it being a manual choice. That's how I understood it, anyway.
We have updated the filter in recent times, so I'm not sure if this is still the case, but I can confirm the name above has been banned.