I was playin around on my server and wanted to create some sort of tower. So, I went on the forums and found this post: http://www.minecraftforum.net/forums/minecraft-discussion/redstone-discussion-and/2203206-guardian-laser-tower-help
It was exactly what i wanted to do.
But when I would run this command in a command block:

/summon Guardian ~ ~ ~ {Attributes:[{Name:generic.attackDamage,Base:100},],CustomName:"Laser",Silent:1b,Invulnerable:1b,Riding:{Invulnerable:1b,Silent:1b,id:"Pig",NoAI:1b,CustomName:"Laser"}}

It would only summon a renamed guardian (no pig or ridding guardian). So, I tried in singleplayer and the same thing happend. I tried in 1.8.8 and the command works properly.