Coffee tweaker?

I was wondering what does tweaker mean. So did google search. Came across some interesting and scary information.

Interesting stuff included this coffee recipe titled :

"Cheap Gourmet" Coffee post by Beautiful Nightmare

Now the scary from Wikipedia on Tweaking and Caffeine

"Tweaking also means to make subtle changes in thought patterns or environment. People who do this to others are referred to as tweakers and can easily be confused as meth users

Tweaker describes the "two week" no sleep, no eat, erratic behavior binges. Hence, the term tweaker."

Caffe Vanilla Frappuccino

Smooth and sweet, you fit in to almost any crowd. No one would suspect you of being a coffee tweaker!

What Flavor Frappuccino Are You?