The Guardian ("Palestinians condemn Israel's prisoner release list"):
The figure includes 183 inmates convicted of activities ranging from stone-throwing to membership of "terrorist organisations", and 139 "administrative detainees" held, without charge, on security grounds
In truth, the list (Hebrew link) includes plenty of people charged with owning and distributing bombs and weapons (eg. "#137 Marzuk Awud Mahmoud Abu Naim - possession of a bomb, contact man for placing a bomb", "#166 Wadia Mahmad Hasin Kabaja - Firing a gun at a person", etc.).
Not to suggest that the rest of the Guardian article is any less vile.
Why should Israel release these dangerous people? Certainly it doesn't work as a "confidence-building measure" or indication of good will....