Is kidnapping a legitimate form of warfare?

Although Israel and the Hamas have effectively entered a cease fire, recent footage from the El-Aktza TV station, official television station of the Hamas, shows instructional videos on how to kidnap Israeli soldiers.

In the videos, a mock armored van is hit by a roadside bomb, when an armed man runs into hit, picks up a wounded soldier, and races away carrying him, while his armed friend serves as backup.

The video was uploaded to youtube and shown in the Israeli media.

Hamas Tv station, also aired a documentary, recently, that portrayed the jews as "satanic" who planned the Holocaust in order to get rid of the weak and disabled.

The film depicted Israel's first prime minister, David Ben Gurion, as saying that  "the disabled and handicapped are a heavy burden on the state."

That movie also claimes that the "Jews thought up an evil plot to be rid of the burden of the disabled and handicapped in twisted criminal ways... They blame the Nazis or others in order to appear persecuted and to try and earn the sympathy of the international community." 

Source.