This document summarizes a presentation about hacking at different scales from the body to the city to the planet. It discusses how hacking involves intentionally altering existing systems for new purposes, both beneficially and harmfully. Examples are given of hacking the body, hacking the city through guerrilla gardening and bike lane modifications, and proposals for hacking the planet through large-scale engineering projects. The presentation argues that hacking the planet through geoengineering may be essential for human survival. It also shows how technology and social networks allow new representations of reality and participation in virtual worlds.