[CobaltBlue]

I think it would be illegal to put it in someone else's house, at least in the US.

Using surveillance in your own house is old news.

[Apogee]

When one has no evidence against a tightly knit clan of abusers, such a toy might be the best thing going. As much as I hate "for the children" type jurisprudence, surveilling your own children might pass muster. A lawyer might tell you to let him worry about admissibility, if you turned up something pertinent.