There's a lot of different ways to do this. One of them would be a displacement map set to displace only vertically. If you create a displacement map with vertical lines (the same width you want the fragments to be) of various grey values, you can use the displacement map effect to break up your text layer.
Overlay a vertical line grid of single pixel lines to create the separation.
That's the basic idea.
Here's a quick way to create the displacement map.
Create a new comp that's the same size as your main comp and call it 'displacement map'.
Create a new solid that's 50% grey.
Add Effects>Noise & Grain>Noise.
- amount of noise 100%
- monochrome noise
Scale this layer only on the Y-axis to the maximum value (1000000).
You should be seeing vertical lines of 1pixel wide, in variable grey values.
Now place this comp in the same comp as your text layer (turn off visibility) and apply Effect>Distort>Displacement Map. Select the displacement map as your displacement map layer, set horizontal displacement to 0, and play around with vertical displacement to taste.
To create wider columns (instead of the single pixel lines) the easiest way is to scale the noise layer on the x-axis also. If you scale it to 200% you'll get 2px wide columns. To avoid the columns from being 'soft' set layer quality to 'draft'.
A quick way to create the vertical black lines is Effects>Generate>Grid. Set size to 'from width and height' and set width to match your columns (for 5px wide columns: set noise layer x-scale to 500% and grid lines to 5 pixels horizontal. Set grid height to a value larger than your comp height and adjust anchor to move the horizontal line out of the frame.