A few hundred years ago, the notion of "theft" was very simple: you take a valuable physical object away from somebody else. In the late 20th century, value shifted from materials to information, with a corresponding shift in the definition of "theft" because information is so easily copied. Thus when you take information from somebody, you're not taking it away, you're merely depriving them of their exclusive possession of it. This has led to the quagmire of modern copyright law, which is nowhere more deeply mired than in its application to computer software.
Such "informational goods" differ from material goods not only in being easily copied, but in not having geographical location. Consider the song "The Star Spangled Banner". The music and lyrics are encoded on a million sheets of paper around the world, encoded differently on a million LP's, tapes, and CD's around the world, and encoded still differently in millions of brains around the world, but where is the song? It makes no more sense to discuss the geographical location of an informational good than to discuss the color of a governmental agency or the filename of the Moon. Many or most of the problems the current legal system has with computer software and the Net come directly from trying to apply to informational goods the centuries-old principles developed for material goods.
Consider import and export control. When governments worried only about the import and export of jewelry, weapons, drugs, and other material goods, they could simply post inspectors at all the major border crossings (not easy in itself!). But how do you regulate the import or export of informational goods? What does it even mean to import or export an informational good that doesn't have a geographical location? This problem arises, very concretely, when governments classify mathematical techniques and computer algorithms as weapons, and forbid their export across national borders, which of course are geographical and therefore irrelevant to algorithms. The cases of Philip Zimmerman, Daniel Bernstein, and Phil Karn might interest you.
Most people reading this are probably in the U.S., and think of the First Amendment right of free speech as a fundamental, universal principle. But in many countries other than the U.S., that right does not exist, or is subordinated to other rights. For example, Canada (not what most people would call a totalitarian state) has chosen to subordinate free expression to certain other laudable goals: preventing inflammatory "hate speech", avoiding O.J. Simpson-style trial publicity, and restricting false or misleading political advertising in the last few days of a political campaign. As John Perry Barlow (co-founder of EFF) put it, "In cyberspace, the First Amendment is a local ordinance." What happens when geographically "local" ordinances are applied to a medium that ignores geography?
Suppose you say something on a newsgroup, or include something in your home page, which is legal where you live but counted as illegal obscenity in Jurisdiction X (which may be a different country, or just a different state or province of the same country). Can a user in Jurisdiction X be convicted for reading what you publicly posted? Can the owner of the computer on which that user read it be convicted for transmitting obscene material? What if the material in question was encrypted before transmission in such a way that the owner couldn't possibly have known that the material was obscene; is the owner still liable? Can you be convicted for posting something which might be accessible from a place where it's illegal?
This has already happened: Robert and Carleen Thomas of California were convicted in 1994 by a Tennessee court for, among other things, posting pictures on a California BBS which were deemed obscene under Tennessee's "local community standards". On Jan. 29, 1996, their appeal was denied, partly on grounds that they knew that some of their BBS users were from Tennessee and other conservative jurisdictions, and could have refused access to such people. The court opinion quotes, more than once, that "venue for federal obscenity prosecutions lies 'in any district from, through, or into which' the allegedly obscene material moves." If this precedent is applied strictly, it could become illegal to email anything obscene in Tennessee from California to New York, since one of the links in the packet-switching chain might be in Tennessee.