Lyric discussion by FilthEBastard 

The song is about union busting. "Someone in this town tried to burn the playhouse down" is in reference to the 1913 Italian Hall incident where an affiliate of the local mines yelled "fire" at a Christmas party being held for striking workers and their families at the theatre in Calumet, Michigan , USA. The incident resulted in a crowd crush and subsequent trampling that caused 73 lost lives and many more injuries. A significant number of the casualties were children. "Throw the crib doors wide, let the people crawl inside" is referring to the "cribbing", the reinforcement beams that hold up the ceiling of the mining tunnels. It's the company saying "give the babies what they want, just reopen the mines" . The rock to wind the string around is solidarity of a union. It's the empowerment gained through a collective bargaining effort, and the prosthetic foreheads they want are hardhats/helmets. The people wanted safety gear and safer working conditions for the miners. The company thought of them as expendable and wanted to silence the spread of a pro-workers' rights sentiment.

[Edit: Left out important details]

@FilthEBastard oh and the opening lyric is because the chaos was created to interrupt the rally and distract people from the cause. The line about being a carpenter and smashing his piglet is saying if he made a decent wage he'd buy his own hard hat, but with the low wages at the mine he'd literally have to break the bank (smash his piggy bank open) and take his entire savings (a paltry $7) to buy one from the company store.

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