The Palestinians started working in tunnels successively after Hamas' takeover amid July 2007. Since then, Israel's stringent blockade forced Gazans to make tunnels as a public phenomenon with by-laws even if not written. Furthermore, Hamas parliamentary bloc held a special session to discussing tunnels and their laws until some Gazans expected a newly imposed "ministry of tunnels"
The network of tunnels in Gaza, are an industry by itself
Also, one thing wrong with this article is that the tunnels have been there ever since before the First Intifada. After speaking with many who work in the tunnels, from students, minors, and elders, all said the tunnels existed from before they were born