Just to confirm, I told Cerberus up front when placing the order that I am snake from the TBB forum. I wanted them to know because, I would be posting on TBB everything that would be happening with my order. They were OK with me doing that.
I don't think you should need to ask for permission when posting about a
genuine service installation experience from any ISP. I certainly didn't ask FluidOne if I could post about my FTTPoD installation experience with them. In any case, its free publicity for the ISP so you're doing them a favour, not the other way around.
However if a poster starts telling stories about fictitious orders (as adslmax has done) then of course an ISP has every right to step in and refute these.