A: The answer has to be a qualified "maybe". Without any protection (including simple WEP) most wireless networks are extremely insecure. With additional security such as WPA/WPA2, two-factor authentication and 802.1x, wireless networks can be made much more secure.
Q: Are wireless networks safe?
A: Bluetooth could be a problem depending on how and where you use it. There are many myths about Bluetooth vulnerabilities. Like any other communication method it should be disabled if not needed. Several options to secure Bluetooth include disabling discovery and using secure PIN's.