Most local area networks, and virtually all public WiFi access points are insecure. Data packets are actually broadcast across the entire network, and unless you establish a secure network connection, your information can be intercepted by others midstream (such as when using packet sniffers).

If you’re on your own private WiFi hotspot, it makes sense to activate encryption and authentication, such as Wired Equivalent Privacy (WEP) or Wireless Protected Access (WPA). However, public hotspots are a different thing altogether, since these usually have WEP and WPA disabled, to maximize the possible number of devices that can connect (since not all devices support either protocol).

If you’re using a public hotspot, here are some tips to keep in mind to be safe:

Use a virtual private network. If you don’t have your own office VPN, several companies offer free VPN services. These let you connect in a secure, encrypted manner into an off-site facility—usually your own—so your data cannot be intercepted mid-stream. Examples include Hamachi and iPig.

Use secure protocols. If you’re accessing your email through the Web, try logging in to your provider using https:// instead of http:// (mind the “S”). This encrypts your communication so that sensitive information is not let out in the open. If you’re using Outlook, set your options to use SSL (or secure sockets layer) so your password is not transmitted over the network as clear text.

Secure your hardware. This is good advice, especially if you’re in public. Most security-related reports relating to WiFi involve laptop theft. So don’t just leave your laptop on your table as you order another latte. Try purchasing a lock cable, which lets you tether your computer onto the table or any fixed object. There are various companies that manufacture these locks, including Kensington and Kryptonite.