Israel routinely kills about 10 times the number of civilians as Hamas but they do not target them.
The reasons why this is so:
1. The security wall has been effective in limiting the ability of Hamas to kill Jews
2. Hamas has realtively ineffective long range weapons
3. Hamas tries to ensure that the maximum number of Palestinian civilians are killed in Israeli counter-strikes
If you gave Hamas a button to push and it killed 1000 Israeli children with every button push they would be pushing the button so furiously that they would develop carpal tunnel syndrome.
There we have your old argument again: If the intention is good, it is ok to kill civilians. Look up what martin Luther said about good intentions.
The numbers tell the story:
Number of people killed by violence:
----------------------Israelis-------------Palestinians
2006.....................23....................... .665
2007.....................19....................... .385
2008.....................35....................... .887
2009......................9....................... 1034
2010......................8....................... ...70