I think the real question got snowed under the brevity of the last few answers, but I'll admit that my answer was worded clumsily and only makes sense in the co

I think the real question got snowed under the brevity of the last few answers, but I'll admit that my answer was worded clumsily and only makes sense in the context of the original question "I'd worry about recording someone who simply bought a "used" phone on ebay - and the legal ramifications of such a move." An unwitting buyer in good faith becomes owner of that phone, because the transfer of the good is, briefly put, valid (articles 3:84 and 3:86 sub 1 of the Dutch civil code). Now it's true that the original owner can revindicate (that is, 'claim back') the phone from the buyer (within 3 years and within some other small boundary conditions). This follows from the exception to 3:86 sub 1 in 3:86 sub 3. I'm saying however that this right to revindication is irrelevant here. My point was (but again I'll freely admit upon rereading it that my wording didn't actually make this point), that the phone at the time of the spying was the fully, legal property of the buyer; and as such, that they have the full legal protection any owner has or would have. So you can't make a legal claim 'oh but that guy who bought it wasn't the owner so we could do with the phone as we pleased'. (Which is what I read as the worries about recording someone who bought a phone off ebay - the worry that the guy who did this could be legally committing the same 'thing' anyone else would be doing when abusing someone else's phone to spy on them). (While I'm not technically a lawyer, I do have a Dutch law degree, although of course that doesn't make me all-knowing and I've often been wrong before)