My first helpful post got deleted because someone incorrectly assumed it was a personal attack. It wasn't. You seem very much overly concerned about security here...to a degree that to me borders closely on obsession. I've helped several people setup networks and deal with securing their house from that perspective.
First:
I always thought why would anyone try to steal my passwords and other information. Someone did hijack my wife's e-mail account last month and sent out an e-mail soliciting money, on account of her being stuck in London, from every one on her address book. Even Delta got one. Delta wrote back apologising for not being able to jelp us. Was this the first time that DL received an solicitation from an e-mail address of Platinum?
That was most likely a virus. There aren't teams of millions of hackers taking the time to break into one machine. They create malware and get that to do it for them. You wife probably clicked on some things she shouldn't have or installed software she though was ok. The chances that someone took the time to that personally are extremely small. You're not that big of a target.
Second:
You either don't mind the relative's son being on your network or you do. You have that choice to make. You seem to want to micromanage that decision and it's the wrong approach. It's either ok in your world or, if it causes you that much anxiety, it's not.
If it's not, make him spend the money to get his own air card or his own internet setup in the house.
If it is, then give him access. Are you a secret agent or something? If you're a normal person and not running NASA then you have little to fear by letting him on your network.
Third:
The likelihood of the Blackberry causing a problem is very small. Him streaming Pandora over your router isn't going to cause someone to hack into some database to change the title of your house to someone else. All of that stuff you see on TV where people hack into various agencies in 2 minutes whenever they want is fiction. It's called filling plot holes. It's not real.
Fourth:
You're letting the guy use a PC on your network. That you'd be worried about the Blackberry makes no sense. The chances of a PC getting infected with something? Very high. The chances of a phone getting infected? Low. He wants his Blackberry on your network because it is faster. A PC is what is likely to be infected with malware, trojans, etc.
Fifth:
You seem extremely concerned about security of your wireless network. Get rid of it. Wire your house. Someone then would literally have to gain physical access in order to use it. Again, unless you're worth $10m it shouldn't matter. It's not like you should have anything that secret on your computer hard drive. Also, in the case where you are a high net worth individual, stop reading this post and go hire a local firm to set all this up.
Sixth:
If you have this much anxiety about any other things in your life and it is common for you to have more concern about many things than a normal individual generally does, you may want to chat with it the next time you have a doctor's appointment. People who micromanage things in their life, are excessively worried about others and have fears that don't bother other people often have issues with anxiety. Should that be the case, then it would not be a bad idea to deal with it.
Seventh:
Have you wife switch to Gmail. It's more secure and the folks at google keep it both spam and hack free. It also gets rid of the need for an address book just for email addresses. That people use the built in Outlook target for email is just a bad idea.
Eight:
A wireless network is ALWAYS insecure. It's just sitting there. No matter what you do, someone can get on that network. You can hide the SSID, restrict the Mac addresses, turn down the radio strength, use WPA2 and the best network settings. Someone can still get on it. The most likely case that this happens is that one of your neighbors doesn't want to pay for internet and uses yours.
Ninth:
You seem very concerned about people hacking your network. You might want to take backups of everything and keep things like Quicken, tax returns, etc, off of your network. You might also want to find some software that will make sure no personal information is left on any machines.
Are you saying there is absolutely no way for a an irresponsible/lackadaisical user of blackberry to make a network or other computers on the network vulnerable?
I think that you're missing there is that it is theoretically possible, but the chances of that happening are enormously small. Know what is likely. Someone hacking windows. The chances of that happening are degrees higher than someone hacking a blackberry. By the way, they wouldn't hack a blackberry to get in to your PC. Regardless, that Blackberry is the most secure thing in your house. That someone who would think it bad to put a Blackberry on a network and ok to put a PC on the network is rather silly. The latter is the problem.
"How unsecure can BB be?. Or how a BB in the hands of an irresponsible user can create a gaping hole in your security".
Your wireless network is one massive gaping hole in your 'security'. Your wife's PC is another one as is every PC in your house. The blackberry is the least of your concern.
Didn't Etisalat install a spyware on its BB users, through a patch that was supposed to "enhance" performance? The spyware was initial turned off, but could be turned on with a command from Etisalat?
It was discovered when some people complained of battery draining quickly.
Aren't there thousands and thousands of pieces of malware released for PC's each year? Didn't your wife's computer get 'taken over'? Did you take that offline and not let it in the network. People here are clearly telling you that the Blackberry is not something you should be worried about? Why even post if you won't accept the answer?