An Imgur user created a photo gallery rounding up items confiscated in prisons that featured some old-fashioned MacGyvering of everyday products. Unsurprisingly, many of the tools are weapons.
"This gun was found along with other homemade firearms in the cell of two Celle prison inmates on November 15, 1984. The weapons had been made in the prison’s metal workshop. They were loaded with pieces of steel and match-heads."
"Whip with razor blades. The grisly weapon was found around 1996 in ‘Santa Fu’ jail in Hamburg, Germany, in the cell of a drug addicted inmate after his failed attempt to extort a higher Methadone ration by threatening a female prison officer with a knife."