A web spider, or web crawler, is a program that scours the Internet for data. Wikipedia has a good description of them. And guess who is starting to use them? The taxman.
The Belastingdienst, the Netherlands version of the IRS, started a program called Xenon in 2004. Four other countries have joined in: Austria, Canada, Denmark, and the United Kingdom. As this story in Wired notes, the goal of the program is to look on the Internet to find individuals and organizations that have not paid their taxes. The spider finds businesses, and using other tools, gets their addresses. The information is then compared to the data in the tax organization’s files to see if that business has filed a tax return. Presumably, businesses that haven’t filed get a knock on the door from the taxman.
Obviously, there are privacy concerns with such a program. But it’s public information that’s being examined, and if you post it on your web site, you had better assume that the IRS (or the foreign equivalent) is reading it.
The IRS is not part of the Xenon project. However, the IRS would not confirm or deny to Wired that they use web crawlers.