The most important ethical issue, the most pressing, is the ethics of the concept of "intellectual property", meaning patents, copyrights, and trademarks, in an age where information has essentially zero cost of transmission and dissemination, and where information and algorithms not of our own construction, biological information, is discovered by private and public entities.
In the past era of print media and mass media, copyrights were required to ensure that publishers could operate in the black. During the French revolution, copyright was briefly abolished, but soon restored, as it was clear that a mechanism was required to ensure that publishers would be protected from plagiarism. The notion of patents was similarly constructed, to fascilitate the description of new inventions, and they were effective well into the latter part of the 20th century.
But with modern information technology, both systems are largely anachronistic, and have been responsible for major setbacks.
- Software copyright: This has been a scourge of the computer industry, single handedly slain with Richard Stallman's GPL. Software copyright, as championed by Gates and Wolfram essentially wiped out software for a decade (1980-1994), and only the development of GNU/Linux allowed the art of programming to be reborn.
- Software patents: I consider these to be ethically repugnant. The idea of patenting algorithms is contrary to common sense and to free software principles.
- Gene patents: the concept of patenting molecules was extended to patents on genes, with absurd results. There is a single corporation that holds a patent on interferon, something which, needless to say, they did not develop. The prior art in this case is at least 60,000,000 years old.
More generally, copyrights on music, art, literature, are all holding back mass dissemination of works. It is especially pernicious in the case of scientific publishing, where the authors would benefit massively from public release, and the publishers, who are already gouging universities, have no moral claim on the content, since they serve no useful role anymore.
The ethical issue is pressing. In this, I think Richard Stallman is the only person who consistently makes sense. Within free software, there is always the issue of artistic control, and Larry Wall has shown the way here.
The young people seem to have already taken matters into their own hands, and have defacto abolished copyright law. It is difficult to see how the same can be done for patent law, which has become an equally pernicious thorn in the side of progress.