Is there any danger of a random ebay one ‘phoning home’ and configuring itself or updating itself in some undesirable way? I suppose many or perhaps all of the ones on ebay are ex BT engineer install ones from the days before they went for the cheapo option of self-install. Is that the case? A BT engineer install one would be ISP-neutral of course, isn't that correct? Would they still phone home anyway? Because, so I believe, in the old days BT delivered a service up to the point of the output of the modem, for a time, rather than to the NTE, as usual. But what do I know. I have no personal experience. Such things remain forever a dream for me, only heard of in tales from distant lands.