True, but the ones that use the dynamic encryption can do a reasonably good job along with a firewall and router. The golden rule is "Nothing is bullet proof"
One of the locals mentioned doing a bit of "war driving" around town just for curiosity. About 80 to 90% of the networks heard were unencrypted AND over half of those _still_used_ the_default_name_and_PW. I use hard wired Cat5e in a gigabit network as with the amount of traffic wireless is just too slow even if it is full duplex.
NOTE I only receive the two amateur radio news groups. Roger Halstead (K8RI & ARRL life member) (N833R, S# CD-2 Worlds oldest Debonair)
I can choose a different special case with a different result. For a large, high-gain aperture-type antenna such as a big horn or dish, virtually the received energy orthogonally incident on its cross-section will be sucked up and absorbed.
Therefore you can't really say that an antenna always radiates at least half the received power.
The driven elements should be resonant and connected to a matched load, while the parasitic elements are off-resonance and not connected to a matched load, but they are just grounded to the (virtual) boom.
Thus, it is quite natural, that the parasitic elements will reradiate any energy from the passing field and hopefully the reradiation from all parasitic elements arrive in correct phase to the driven element, to form the desired radiation pattern.
======================== You probably mean 'shame on the users' who haven't got a clue.
By the way it is the same situation here in the north of Scotland . Driving in Inverness you can freely access WiFi points allover town ,from commercial companies to hotels..........but not at locations where you would expect it ....like 'Starbuck' and bookshops like 'Borders' Also in California you have to pay for WiFi access at Starbuck.........must constitute a increasing part of their income,considering the number of people with laptops.....usually without a coffee..
This will go on until the Scotish police start doing what the English do. They track traffic at the ISP level looking for "kidde p*rn". Once they find it, they locate the person sending or receiving the files.
They have no trouble getting a warrant and come in and arrest the owner of the account and confiscate their equipment.
As soon as they do this, "users" will go looking for unencrypted networks and use them, if they don't know I don't know Scotish law, but in most places the owner of the network is responsible for what is done with it.
There was a case in Canada of a man found driving five miles per hour in a residential neighborhood. When the police stopped him, his pants were around his ankles and there was a laptop on his lap.
Canada unlike most places has a law prohibiting using other people's internet connections without permission. Most places don't.
On Tue, 11 Jul 2006 10:53:18 +0100, Highland Ham wrote in :
No, I mean shame on the wireless hardware companies, as I wrote, for such a gross disservice to their customers -- it shouldn't be necessary to be an IT expert to use Wi-Fi safely. It should just work properly. Otherwise it's not ready for the market.