Which means an essential part of any legislation may be compelling them to allow better monitoring, though not something we necessarily want to happen given the risks more surveillance brings.
Ultimately though 'today's tools cant do the job' means nothing more than it says, 'today's tools'. Arguably a signal of abuse must be detectable, otherwise no one is actually being abused. Once detected the tool of legal compulsion can be employed to dig out the truth. If the carriers are smart they'll not risk that anal probing level of investigation.