Some broadband users – particularly those on the budget ADSL plans with only 200MB download allowance – find that they have to closely monitor their internet usage to avoid excess usage charges from their ISP. Sometimes they notice that their internet usage increases even when no-one is at their home/office.

The first thought is usually “hackers” … but there is often a much less sinister cause.

The trend is increasingly to focus on convenience for the user, and to assume a high-speed internet connection with no download limit; so making their programs user friendly often involves accessing the internet at regular intervals. For Example:

  • By default, Microsoft Outlook (and other email programs) check for incoming email every 5 or 10 minutes. Each send/receive sends a small request to the email server and received a small “no mail” acknowledgement. A trivial amount of data transfer … but if it is done every 5 minutes for several email accounts, it can add up to a fair chunk of a 200MB allowance. If you don’t need to know the minute that an email arrives, you can reduce the frequency of automatic send/receive; or even turn off the automatic checks and click the send/receive button manually.
  • Windows Automatic Updates downloads and installs any new patches to Windows and other installed Microsoft software in the background without your knowledge. Some of these can be quite large. Many other companies are following Microsoft’s example.
  • Peer-to-peer (P2P) software such as Kazaa, eMule, Limewire, BitTorrent are very popular with teenagers for transferring files in the background. Note that any files downloaded are then shared with other P2P users, and that P2P programs maintain connections with other P2P users even when no files are being transferred. Fortunately most P2P programs can be configured to limit their effects.

If you have a Wireless Access Point (WAP) on your network (maybe a wireless router), you should implement one or more of the security measures built into the WAP to prevent your neighbours from joining your network and using your internet connection. The newest and best encryption is provided by WPA2, but one or more of your wireless devices may not support is, requiring you to compromise on WPA, WEP 128-bit or WEP 64-bit encryption. See our discussion of wireless security.

There is always the possibility that one or more of your computers may have been infected with a virus, spyware or Trojan. While Anti-Virus software is run on almost every PC these days, anti-spyware software is not so widely understood, with some people believing that their anti-virus program provides total protection. The truth is that a virus is just one category of “internet nasty”, and that no single program can protect you from all of them. is a good starting point for finding about Spyware, including their recommended programs  (both free and commercial).