The torture of this device may not seem all that bad, but at the time it was awful. Around the time periods it was used, peoples lives balanced on reputation, if anything arose in their life that would humiliate them like a child who stole something, it is the equivalent to be homicidal pedophile today. Stocks were only really used for the restraint of the ankles and sometimes other limbs.
When your out in the stocks animals might eat you, people throw stuff at you, and your exposed to the weather. Not a very horrific device but effective at the time...