As any computer user employs the Internet to accomplish everyday activities, a flow of data packets moves across the network, forming their own patterns in response to his or her actions. Artists and sound designers who are interested in accessing that data to make music must currently possess low-level knowledge of Internet protocols and spend signifi-cant effort working with low-level networking code. We have created SonNet, a new software tool that lowers these practical barriers to experimenting and composing with network data. SonNet executes packet-sniffng and network connection state analysis automatically, and it includes an easy-touse ChucK object that can be instantiated, customized, and queried from a user’s own code. In this paper, we present the design and implementation of the SonNet system, and we discuss a pilot evaluation of the system with computer music composers. We also discuss compositional applications of SonNet and illustrate the use of the system in an example composition.