For anyone who gets a copyright infringement notice, don't respond to it. Repeat, don't respond to it.
Responding to the notice allows them to start on the track to identifying you and sending more extortion notices.
The notice falsely warns that the recipient could be liable for up to $150,000 per infringement when the reality is that Canadian law caps liability for non-commercial infringement at $5,000 for all infringements. The notice also warns that the user’s Internet service could be suspended, yet there is no such provision under Canadian law. Moreover, given the existence of the private copying system (which features levies on blank media such as CDs), some experts argue that certain personal music downloads may qualify as private copying and therefore be legal in Canada (Howard Knopf explains the applicability when the music is copied to “audio recording medium”).
In addition to misstating Canadian law, the notice is instructive for what it does not say. While a recipient might fear a lawsuit with huge liability, there is very little likelihood of a lawsuit given that Rightscorp and BMG do not have the personal information of the subscriber. To obtain that information, they would need a court order, which can be a very expensive proposition. Moreover, this is merely an allegation that would need to be proven in court (assuming the rights holder is able to obtain a court order for the subscriber information).
SonyBMG put rootkits on music CD's in 2005-2007. They paid an extremely small fine and none of their executives went to prison for their crime. Point that out to the Judge if you ever get extorted. A snippet of data that your IP address file-shared is not the entire works and should never used as an instant guilty verdict. Don't be led to believe that you have to travel cross country to defend at any potential trial. Let them come to your infringing location or do it via video court.