I have a wireless router in my room, am I responsible for what is downloaded using my wireless connection?

Yes!  As stated in the NU Appropriate Use Policy (AUP), owners/operators of routers and/or wireless access points are solely responsible for the security and access control for their devices, and are liable for the actions of anyone accessing ResNet through their device(s). If another person uses the internet via your wireless router to download illegal content, YOU will be held responsible for that illegal activity. Be careful when allowing others to access the internet via your wireless router. 

For more information:

Wireless Router / Access Point Security Recommendations and Requirements

Wireless Access Points – Set Up Examples

Northeastern University Appropriate Use Policy (AUP)