My retainers have been pilfering a materia warehouse for the last week and still continuing.

My female Lalafell brought back a PVP Healer belt. -_-
I can just imagine her running into the fray, cackling maniacally, ripping off the belt and this poor hapless healer standing there, breeches around the ankles as she runs away. My male Lala retainer brought back a PvP Bracelet of Casting last night.

Aside from the usual materia, PvP gear and the rest of the ilvl70 Green weapons and gear, they bring me roof tiles and bronze rings.
I agree, the Thief Guild has been here all the time.