Sodium Hydroxide (which is the active ingredient in many drain cleaners, including Drano (Drano MSDS Here)) does indeed react fairly violently with aluminium to produce Hydrogen gas.
2 Al + 2 NaOH + 2 H2O → 2 NaAl(OH)4 + 3 H2
The Sodium Hydroxide breaks down the passivation layer that naturally forms on the surface of aluminium due to it's reaction with atmospheric oxygen. It's my understanding that:
- The Sodium Hydroxide dissolves the passivation, which allows the NaOH and H2O to come in direct contact with the Aluminium metal.
- The Aluminium reacts to give NaAl(OH)4, and hydrogen as a gas ultimately ending up with a lot of heat, hydrogen gas, and various aluminium hydroxide species.
I do not know if it has been used maliciously as described, though.
To clarify, in the configuration used in the "prank" (vandalism?) described in the OP:
The aluminium and sodium hydroxide are not mixed initially inside the bottle.
Basically, there is some sodium hydroxide solution in the bottom of the bottle, and the aluminium foil piece is hung/balanced above the solution in a manner where jostling/tipping the bottle will cause it to fall into the sodium hydroxide.
Therefore, the reaction is triggered by the bottle being moved, and it could (theoretically) sit for a significant amount of time before being triggered. It is probably quite hard to control the reaction speed with commercial drain cleaners but it is clear that it can sometimes be fast enough to be dangerous.
My chemistry vocabulary is really rusty. Corrections welcome!