To get this you need to use three Power to the People machines on the same weapon.
There are 14 Power to the People stations.
Power to the People #1 (Ryan Amusements)
Power to the People #2 (Ryan Amusements)
Power to the People #3 (Pauper's Drop)
Power to the People #4 (Pauper's Drop)
Power to the People #5 (Pauper's Drop)
Power to the People #6 (Siren Alley)
Power to the People #7 (Siren Alley
Power to the People #8 (Dionysus Park)
Power to the People #9 (Dionysus Park)
Power to the People #10 (Fontaine Futuristics)
Power to the People #11 (Fontaine Futuristics)
Power to the People #12 (Persephone)
Power to the People #13 (Inner Persephone)
Power to the People #14 (Inner Persephone)
Please see linked site for exact locations
http://m.au.ign.com/wikis/bioshock-2/Power_to_the_People_Loc...