Activists and inmates say the strike is meant to call attention to inhumane conditions in Pelican Bay's Security Housing Unit (SHU), where dangerous prisoners are lodged in small, windowless cells, often without access to other people or open space for extended periods. Critics of the SHU say that solitary confinement is equivalent to psychological torture, a position that is buttressed by recent scientific research.Here's a more current update from The Nation.
Or, as Johann Koehler relates it to In Defense of Flogging in a thoughtful blog post:
The question of whether you’d prefer flogging instead of prison is nowhere near as grotesque as whether you’d prefer to starve yourself to raise awareness than tolerate another day of institutionally sanctioned torture. One is a fanciful thought experiment. It’s fiction. For 400 people, the other is acutely real.