I had a quick chat with a friend last day and he was complaining that someone was maybe attacking him, using the same ESSID. He was very upset and wish to have a resolution, so he called me for an advices… most of the time we forget that every day you are working with wireless is a gift. Unless what happens in a wired world, radio waves travels in the air and air is not own by anybody. Whatever he was under attack or not, radio waves can’t be stopped: it is not something we can confine or leave outside the door or the building. Therefore, in the unlicensed spectrum (2.4GHz and 5GHz are in this category), everyone owns the right to allocate a wireless LAN (ESSID) and there’s nothing you can do. This is the ephemeral of wireless.