Schneier on Security

Every year, an army of hackers takes aim at the tax code.

The tax code is not computer code, but it is a series of rules—supposedly deterministic algorithms—that take data about your income and determine the amount of money you owe. This code has vulnerabilities, more commonly known as loopholes. It has exploits; those are tax avoidance strategies. There is an entire industry of black-hat hackers who exploit vulnerabilities in the tax code: We call them accountants and tax attorneys.

Hacking isn’t limited to computer systems, or even technology. Any system of rules can be hacked. In general terms, a hack is something that a system permits, but that is unanticipated and unwanted by its designers. It’s unplanned: a mistake in the system’s design or coding. It’s clever. It’s a subversion, or an exploitation. It’s a cheat, but only sort of. Just as a computer vulnerability can be exploited over the internet because the code permits it, a tax loophole is "allowed" by the system because it follows the rules, even though it might subvert the intent of those rules…