Suburban forage at the most here. But - yes it is to be encouraged.
one should be aware of the "stealing by finding"laws but for the most part urban forage is a fine way to reduce and reuse
i was trained by jedi skip divers and i still use the force,the recent stuff is a gas meter cupboard,2 interior windowsills and a fender from a fire surround and a piano lid ,all indecent quality antique oak
it requires similar skills to ray mears type foraging.