Personally, I think one should not use wireless if he/she doesn't know how to secure it. If they use internet banking on their PC, their banking details and password could be easily sniff out by the hacker.
Your mac address will be captured in his wireless network. If the owner find out that someone is hacking into his network, you will be in trouble.
Several ways to make your wireless network secure:-
- Enable Wifi Protected Access (WPA), apply to new G series wireless modem only
- Enable Wired Equivalent Privacy (WEP)
- Restrict Mac Address(s)
- Do not broadcast your SSID
1) change the default SSID (i.e. the network name of your wireless)
2) disable SSID broadcast (to keep pesky neighbours out since only you would know the SSID and they should not be able to sniff the SSID)
3) Turn WEP on (WEP is to encrypt the wireless communication, not the data that flows within it)
4) change default password to admin page
5) for the paranoid, enable MAC filtering (i.e. tell your wireless router to only serve those computers you specify)
BTW, changing MAC address is possible with some *hack* utility
and the most important thing in security, have integrity and not snoop at your neighbours computer stuff.