As with nearly everything, it depends on implementation.Doubtless there is some post from the original occupants. So you could use their names.Other people say that it's a concern, but it clearly depends on how long the previous occupants has been gone.One useful aspect of this strategy is foreclosed houses may have websites which show you how long they've been about, when visits/open days are happening etc. And of course phone calls to the realtor aren't remotely suspect.