Pakistan suicide bombs kill 80 to avenge bin Laden
In claiming responsibility, the al-Qaida linked militant group cited anger at Pakistan's military for failing to stop the American incursion on their soil.
The blasts in the northwest were a reminder of the savagery of Islamist insurgents in Pakistan. Tensions also have risen between the U.S. and Islamabad over allegations that some elements of Pakistani security forces had been harboring bin Laden, who died in a May 2 raid in Abbottabad, a garrison town about ...
http://news.yahoo.com/s/ap/20110513/ap_on_...

They are angry because their leader has been killed by the enemy.
So in retaliation, they kill 80 Muslim men.
That will teach their enemies a lesson.