PIGGYBACKING

To attach or append something to another (usually larger) object or event.

"The popular host can’t claim credit for the trade, though. The idea wasn’t his. He piggybacked off another successful investor who had a history of picking winners."

To obtain a wireless internet connection by bringing one's own computer within the range of another's wireless connection without that subscriber's permission or knowledge.

To utilize "last-mile" wiring rented from a larger owner ISP by a smaller ISP.