Bone of contention is this topic with us, at the moment. Not something I can go into, either.
However, a bridged-tap will normally see a degradation of service and normally the ISP will report this to OR, and we go round to fix it.
Who pays for this service, we don't get to see ......... but IMHO it should be the ISP, as if the EU had been offered a 'Managed Install' when placing the order, the bridged-tap would have been identified immediately and removed.
However, it seems 'Self installs' have taken over the UK for the last 12months.