Israel withdrew from Gaza in 2005, why are Israelis being attacked?

Amnesty International mentions in this report:

• Although Israel withdrew ground troops from the Gaza Strip in 2005, it maintains an illegal air, sea and land blockade on Gaza and maintains a so-called “access-restricted area” or buffer zone within Gaza. These have cut off more than 2 million Palestinians from other parts of the Occupied Palestinian Territories and the outside world for 10 years.
• As well as controlling where Palestinians can go and who they see, Israel also controls and arbitrarily restricts their access to safe, clean water. Water consumption by Israelis is at least four times that of Palestinians living in the OPT.
• The hundreds of Israeli military closures across the West Bank such as checkpoints, roadblocks and settler-only roads, as well as the overall permit regime, make simple daily tasks for Palestinians who are trying to get to work, school or hospital a constant struggle.