Snowden long ago confirmed that all smartphones including yer all-American(not!) made-in-China Stars'n'Stripes iPhone can be used as Trojan horse audio / video surveillance devices by the likes of the CIA/NSA. Irony is that they're all made in China - and the NSA/CIA loves 'em even more since "non-removeable" batteries were forced upon us.
At least you can wrap a phone in aluminium and stick it in your microwave. A few hundred packs of bacofoil should suffice to foil yer average evil Chinese spy-crane I reckon..