I have to disagree that the knock-on effects of this case (albeit ground-breaking in terms of confirming employment rights for au pairs) means that contracts of employment and tax registration would have to be implemented for babysitters! That's a real stretch (unless the babysitter is a de facto childminder due to the number of hours being worked).  It will be interesting to see whether the other 40 cases are heard, and whether any family, who has correctly utilised the system is found to be compliant.