Life as a patent troll is hopefully set to get more difficult. In a memo describing patent trolls as a “drain on the American economy,” the White House this week outlined a number of steps it is taking to stem this evil tide. Chiming in, the Chief Judge of the Court of Appeals for the Federal Circuit (where patent cases are heard) in a New York Times op-ed laments the toll patent trolling is taking on the industry, and urges judges to use powers already at their disposal to make the practice less attractive. However, while certainly a step in the right direction, these measures all fail to address the more fundamental properties of the patent system allowing trolls to exist in the first place. Continue reading
In recent weeks, a number of high-profile events, in the UK and elsewhere, have been quickly seized upon to promote a variety of schemes for monitoring or filtering Internet access. These proposals, despite their good intentions of protecting children or fighting terrorism, pose a serious threat to fundamental liberties. Although at a glance the ideas may seem like a reasonable price to pay for the prevention of some truly hideous crimes, there is more than first meets the eye. Internet regulation in any form whatsoever is the thin end of a wedge at whose other end we find severely restricted freedom of expression of the kind usually associated with oppressive dictatorships. Where the Internet was once a novelty, it now forms an integrated part of modern society; regulating the Internet means regulating our lives. Continue reading
Outrage was the general reaction when Google recently announced their dropping of XMPP server-to-server federation from Hangouts, as the search giant’s revamped instant messaging platform is henceforth to be known. This outrage is, however, largely unjustified; Google’s decision is merely a rational response to issues of a more fundamental nature. To see why, we need to step back and look at the broader instant messaging landscape. Continue reading
Reading about various patent litigation cases, I am struck by the frequency with which common logical fallacies such as the Appeal to Consequences are committed. We shall look at a couple of recent examples. Continue reading
Use of pointers in the C programming language is subject to a number of constraints, violation of which results in the dreaded undefined behaviour. If a situation with undefined behaviour occurs, anything is permitted to happen. The program may produce unexpected results, crash, or demons may fly out of the user’s nose.
Some of these rules concern pointer arithmetic, addition and subtraction in which one or both operands are pointers. The C99 specification spells it out in section 6.5.6:
When an expression that has integer type is added to or subtracted from a pointer, the result has the type of the pointer operand. […] If both the pointer operand and the result point to elements of the same array object, or one past the last element of the array object, the evaluation shall not produce an overflow; otherwise, the behavior is undefined. […]
When two pointers are subtracted, both shall point to elements of the same array object, or one past the last element of the array object; the result is the difference of the subscripts of the two array elements.
In simpler, if less accurate, terms, operands and results of pointer arithmetic must be within the same array object. If not, anything can happen.