I know why they're crashing
As a BT customer for phone and broadband (and a loyal one at that), I'm dissapointed that BT is suffering but I can see why.
They recently asked me to extend my contract to 18 months in return for a small discount on my monthly bill. When I said that I would extend my contract if they could deliver the speeds they claim are possible at which point they offered to send an engineer out (at a cost to me) to replace some of the wiring that handles my broadband.
Because they won't do this for free I've cancelled my contract and arranged for fibre optic broadband, TV and phone from Virgin who are totally independant of the BT infrastructure. All Virgin will have to do to keep me as a customer is maintain the service I pay for and occasionally offer me an upgrade. BT have lost a long standing customer and may never see another penny from me and I bet I'm not the only one. I fear BT's days are numbered.