There is a new Firestorm viewer release which, amongst other things, they say has fixed the audio leakage from parcels when media is on a prim. This is great news, as it's one of the really annoying things that the Estate Managers have had to deal with.
There are lots of other fixes/updates of course, but I thought this particular one would be of interest to the LUC. From the Firestorm changes of notice:
Parcel Media: LL has made it possible for parcel owners to restrict media on a prim (MOAP) to their own parcels and prevent external MOAP from being heard inside the parcel.