Data interception and theft
Introduction
Each time any communication is sent across a network, whether it is a Local Area Network or a Wide Area Network, it is split up into packets and sent by various routes. As they travel from one part of the network to another, they are at risk of being intercepted, read, altered or deleted.
How to intercept data
One way data can be intercepted is if someone uses some hijacking software and pretends to be the destination for communications across a network. Another way is for a user to use 'packet sniffing' software and hardware to monitor network traffic and intercept those packets it is interested in. People using packet sniffers are especially looking for plain text files, passwords and set-up information being set across the network, which they can steal, analyse and extract information from.
Hotspots
The reason why it is not sensible to access accounts such as bank accounts or use your credit or debit cards when in a hotspot or other public WiFi place is because of packet sniffing software. It is easy for criminals to download free software and then use it to monitor and intercept your communications in these places. They are particularly looking for people who log in to bank accounts or use credit and debit cards whilst using a hotspot. The best way to protect yourself is to never use hotspots. Many people underestimate the risks involved. If you know you are likely to use a hotspot, then you should always use a Virtual Private Network (VPN). This provides an encrypted 'tunnel' through which all of your communications will pass, even when using a public network.
Legal data interception
Police and other intelligence agencies can use this technique to legally intercept communications as part of their investigations into criminal activities.
Anti-theft measures
The best way to ensure that your data is safe from interception is to ensure it is encrypted. As mentioned before, you should always use a Virtual Private Network (VPN) wherever possible. This provides an encrypted 'tunnel' through which all of your communications will pass, even when using a public network. If someone intercepts your packets, they will be unreadable.