is it safe to say they will only know if someone tells them?

[Omari]

@Home does not routinely monitor the activity of accounts for violation of this Policy. However, in our efforts to promote good citizenship within the Internet community, we will respond appropriately if we become aware of inappropriate use of our Services. Although Excite@Home has no obligation to monitor the Services and/or the network, Excite@Home and it various affiliates and partners reserve the right to monitor bandwidth, usage, and content from time to time to operate the Services; to identify violations of this Policy; and/or to protect the network and @Home users.