Illegal file-sharing can expose your computer to dangerous software such as viruses (which can corrupt files or damage your computer), trojans (which allow hackers access to your computer), spyware (which monitors your computer use for personal information) and adware (which causes popups and ads to appear). Any of these can damage your computer and place your personal information at risk, and can enter your computer through fake files being shared, or through the websites on which illegal copies are found.
The websites providing access to illegally shared files are almost always run for profit and are funded by advertising. As most reputable businesses are understandably unwilling to be associated with illegal sites, 99% of this advertising is made up of ads for the sex industry, gambling sites and scams. You should be wary of what your family may be exposed to if they visit these sites.
As sharing copyrighted works without permission is harmful and illegal, copyright holders have been empowered to take action against those who infringe copyright through illegal file-sharing. If your internet account is being used to illegally share copyrighted works, you may be served notices under section 122 of the Copyright Act. If so, you will have plenty of time to respond to these notices and/or ensure that any sharing is stopped (see: what to do if you receive a notice under s 122) – but if you persist in sharing files illegally you may be ordered to pay by the Copyright Tribunal (see Copyright in NZ section for more info)