There will be spoilers. Please be wary.
Cartoons from the 80s permeated much of my childhood, largely because a lot of older shows were aired in the Philippines, like the Captain America segment of The Marvel Super Heroes.1 Most people who grew up in the 90s have been exposed to Transformers, however, and know exactly what I’m writing about when I say that at one point Megatron didn’t transform into a tank or a jet, but a gun.2
Beginning in 2007, director Michael Bay began creating films based on the franchise, the content of said films fitting more in line with current cultural norms. In other words, the level of violence was ramped up to much higher levels.3 I never saw a transformer go down when watching the cartoon, but in the first two films we are witness to Optimus Prime, the leader of the Autobots: ramming his Energon Sword through Devastator’s head/neck region4, cutting off Starscream’s arm and clubbing him in the face with it5, and ultimately killing Grindor by pulling his head apart with hooks6.
As the antagonists in these films, the deaths of the Decepticons are seen as victories and not tragedies. Their design, especially when it comes to their sharp teeth and red eyes, helps to depict them as more beast-like than human. The Autobots being seen as people, however, is a point that’s pushed pretty hard in Transformers: Dark of the Moon, the third and final instalment in the series. Wheeljack, the elderly inventor of the Autobots, is captured by the Decepticons and, as he begs for mercy, brutally shot twice. Ironhide is betrayed by Sentinel Prime and shot in the back, and as he asks why the Prime “dismisses” him and deals a finishing blow. Sam [Shia LaBeouf] and Bumblebee have a relationship going back to the first film, and whenever the Chevrolet Camaro-transforming robot is endangered the audience feels as Sam does, taking emotional cues from his panicked yells.
Since the first film we’ve seen Optimus Prime lay down the law and watched him and the Autobots wage their righteous war against the Decepticons. In spite of them clearly being in the right [no one wants humans to become slaves to the Decepticons] some of the actions that they perform in the third film seem . . . excessive. One battle is concluded by Ironhide pulling a spear out of his shoulder and impaling it into Crankcase’s (a Decepticon) face, slamming him into a car, and then kicking the wreckage into an auto shop.7 More disturbing by far, though, is what happens when a Decepticon aircraft is brought down. As the pilot struggles to get out he is surrounded by Autobots and dismembered. His head, arms, and legs are all yanked from his body, with his torso being further pulled apart by one of the Wreckers. Optimus Prime ends the carnage (and the film) by finishing off Sentinel Prime in a fashion eerily similar to how Wheeljack and Ironhide were, by executing him with Megatron’s fusion shotgun as he begs for mercy.
As exhaustive as this post seems to be, there are many instances of robot carnage which I have neglected to include. I suppose that the ones mentioned could show us that extreme violence can be justified when it is the forces of good against the forces of evil (and when they are robots). What it doesn’t explain is how, exactly, to understand this. If the Autobots are to be seen as people then why aren’t the Decepticons? Their fight is a civil war, and with this in mind would we be so cavalier to promote the murder of brother by brother? Are there any real-life parallels that these levels of brutality can be placed on?
The well-known Transformers theme song has the line “The Transformers! More than meets the eye!” The lesser known lyrics immediately proceeding that are: “Autobots wage their battle to destroy the evil forces of the Decepticons!” Knowing this, I suppose we always knew as children that Optimus and his forces were destined to more than defeat Megatron and his cohorts. A dozen or more years later, what I don’t think we could have known is how brutally this would happen.
1. First syndicated on US television in 1966: [http://en.wikipedia.org/wiki/The_Marvel_Super_Heroes]
2. Specifically a Walther P-38, a World War II era handgun. Source: [http://en.wikipedia.org/wiki/Megatron_(Transformers)#Dreamwave_Productions]
3. Levels that can only really be described as Bay-esque. 
4. For your viewing pleasure: [http://tfwiki.net/w2/images2/thumb/5/52/Movie_Bonecrusher_dies.jpg/800px-Movie_Bonecrusher_dies.jpg]
5. Source: [http://www.youtube.com/watch?v=-T-ehTYfE-0#t=00m38s]
6. Source: [http://www.youtube.com/watch?v=-T-ehTYfE-0#t=00m46s]
7. Which then promptly explodes. Courtesy of Michael Bay.