A million times THIS! I am a PT user and am already irritated by the conversations I have to overhear.

The ONLY way to manage this inane problem on PT, if it must be allowed, is to enforce "quiet cars", as Amtrak has done on the Eastern Seaboard...of course, then everyone's fighting for a spot in the QC, but at least I don't have to listen to those in the Loud Car (?is that what we call it by default?)!