A few years ago, a fellow expat friend of mine received a letter in the mail. When she opened it, she found out that she was being charge 1000 Euros for illegally downloading a movie. Having only recently returned to Germany from Korea, she was shocked; while she did download movies over torrent software in Korea every once in a while, she hadn't even started the program since she was in Germany. She check her computer, and it turned out that yes, it was true: when she had turned her computer on three weeks prior, someone had uploaded a file from her computer, and now she had a fine in her hand for 1000 euros, an amount she couldn't pay.
This is a common lesson, and one that many students, both Germans and internationals, learn the hard way. Many students who move to Germany come from countries with much more lax intellectual property laws, which leads them to assume that downloading a movie here or there shouldn't be a big problem. But the German government takes illegal downloading very seriously, and levies heavy fines for each infraction. The laws here are even more stringent than those in the United States, not even giving downloaders one or two free "strikes" before fining them.
Because of this, when you move to Germany, it's important to delete all torrenting software off your computer. Often, services like BitTorrent will automatically begin running in the background when you turn your computer on, and even if you don't actively download anything, you can still be punished if someone uploads something off of your computer illegally. If you do receive a letter like the one my friend was sent, contact an attorney immediately. An industry of lawyers has sprung up as a result of the strict intellectual property protections in Germany, and even though you will have to pay the attorney, it will likely cost you less than it would to just pay the fine. A lawyer will also ensure that you don't incur any additional fines by explaining the laws in depth, thus hopefully helping you to avoid making the same mistake in the future.