This film is silly, and not in a good way. Any film you have criticised in the past for farfetchedness or implausibility will be put into perspective by this truly ludicrous film.
Firstly, all characters are wholly flat and featureless; there is no depth or anything of interest in any of them, the film is just comprised of stock characters. Gerard Butler co-stars as 'Clyde Shelton', a seemingly omnipotent God-like figure who appears to be stronger and more capable than the FBI, the Philadelphia Police Department and various other judicial bodies combined. He's on a mission to correct the judicial system, which he deems to have failed him after the murder of his wife and child. His extraordinary tactility and expertise are tenuously explained in a frivolous scene in which a back story is given to Shelton, a cliched story of how he was a human disposal expert, the character predictably saying "He was the best". His superhuman capabilities are all very convenient, but I don't think he's all that bright, he clearly makes everything much harder for himself. Once the credits roll, it becomes apparent that the plot has one gaping hole, there was no reason for Clyde Shelton to want to be in prison, it would be a completely illogical decision for him to want to be there; you'll know what I'm talking about if you decide to see it. Besides this fatal flaw, there are the ways in which he exacts revenge, they become increasingly nonsensical and boring as the film progresses.
All of this absurdity is fatally compounded by the fact it takes itself seriously. I expected to enjoy this film in a similar way I enjoyed 'Commando', a film which is implausible too, but works through caricatures, hilariously bad acting and fantastically corny one-liners. In 'Law Abiding Citizen' however, there was barely a grain of humour. Despite this, the film gave me one laugh, a scene in which a particularly irritating, somewhat cliched character is inexplicably killed by means of a maliciously modified mobile phone.
This juvenile, unbelievably far-fetched narrative means Law Abiding Citizen is boring. It makes the mistake of adopting a serious approach on a script that appears to have been written by an eleven year-old, but even with humour and interesting performances, I doubt this film could be salvaged. The film is just a brain dead heap of cheap viscera manufactured for the multiplexes; it speaks volumes for today's audience's tastes.