On the face of it, a couch potato isn't a person. Many teenagers are couch potatoes. Thus, it follows with logical necessity, many teenagers aren't persons.
This conclusion is more troubling than the fact that a senile old bag isn't a person, because teenagers are the future, whereas old bags are the past and we can't change the past.
Intuitively, pissing on a teenager while he watches TV is bad. Not the same can be said about urinating on an infected potato or a wasted towel. Intuitions about pissing on a house pet or an ant-hill aren't as clear-cut.
Philosopher Harry Frankfurt famously argued that personhood is defined by having a will. Having a will is basically having an answer to the question of what you want to want. An animal, for instance, wants to have food, but it is no concern of his whether he wants to want food. By contrast, an obese human being may want to eat but may not want to want it. In other words, her will is not to eat and gorging on that bucket of KFC isn't in accordance with her will. Rather, it shows that her will is weak. Having a will is also connected with fighting towards a certain identity. The obese person wants to be a healthy or good-looking individual.
Using Frankfurt's criterion we may ask: does a puberty stricken couch potato have a will? Intuitively, their vegetative brain will be unable to produce an answer if electrocuted by the question "Is there something you want to want?"
It isn't clear that such organic urinals have a will, they are rather in an intermediary level of evolution between apes and man. The value of education is in introducing them to personhood.
If we decide that these decomposing tubers have a will, then we can say either that their will is weak or that being a vegetable is precisely what they want to want.
I think the first option is more plausible. The average teenager may dream of being a rockstar or some type of hero but find himself unable to unglue his sweaty body from the couch.
To the suggestion that the teen wants to want to watch TV we can reply as follows. If we teleport him to a party or something else he finds fun, he won't think of watching TV anymore. He won't leave the party with the express purpose of finding out what happened in the last episode of Glee or what went down in The Bachelor. Unless, that is, their contamination reached extreme levels. In general, having his eyes glued on the tube isn't the teen's project, but just a symptom of being defeated by boredom and lack of imagination.
So, it is plausible to argue that the puberty stricken couch potato has a weak will. They may dream of being Lady Gaga, let's say, but be at a loss as to where to begin the journey to their inner diseased whore.
Another related and central question is: are such weak-willed teenagers free? or is a strong will a central mark of a free will?
It seems right to say that they have a free will. In other words, no one forced them to want to want to be rockstars, for instance. However, their free will is weak and feeble; it doesn't move them into action. But at the same time it looks like they aren't free as agents in the sense that they are addicted to watching TV or playing video-games. So then, while they exercise free-will they aren't free persons. But then what good is free will? Do we only value a free and strong will? Does a free individual have to have an iron will?
If yes, it follows that if we want a healthy society we shouldn't only strive to turn teenagers into persons, but into free persons. That is, into strong-willed individuals, people with strong characters and determination. However, my intuition is that an iron will is only a necessary condition of individual freedom, not a sufficient one. Is someone free if they want to want to be a rockstar while everyone else has that project? Or do we say that he's a victim of trends and cultural manipulation? In other words, it looks like a strong-willed rockstar wannabe is just as repulsive as a rotting, reeking couch potato.