Can anyone shoot me through the internet?
They can certainly attempt to find out where you are, what you do, how you get to work, how you get to places and the like through the internet if someone was so determined to do so. And then meet you face to face to commit the deed.
Additionally, I assume you also go outside on a daily basis as well. This would be the same as going into a metal tube that is 200 or 300 metres long and 15 metres wide. What I mean is, a plane is a private place that is rented out to the public to use, if the member of the public wants to go to the destination and has the money to pay for it.
In a city, you are FAR MORE likely to be killed/run over/murdered by a crazy dude than in a plane itself. You meet many more people in a public open space in a city. Far more than you ever would in a plane. Additionally, there would generally be more chances of something dangerous or life-threatening happening to you in that city every day, than being in a metal tube that is flying at 35,000 ft screaming along at 500+mph.
So, you should trust no-one everywhere, not just the airports. Additionally, you should not even attempt leaving the house, if you were to completely follow this "trust" assumption you have. Or never to interact with people as you cannot trust them as you are not privy to their inner thoughts and desires.
It is only a comment about the "trust" factor, nothing else.
BTW: I generally have no issues with flying as presumably the pilots all have to be trained to a high standard and are responsible for a multi-million quid plane that they cannot crash under any circumstances (apart from mechanical failures). Having the lives of nearly 800 people (Airbus A380 type) AND the cost it comes with would certainly make even the most brazen and cocky individual pause for thought and act responsibly.
Some people seem to associate flying planes as driving a car. Its not. Its a massive responsibility to fly a plane that is only given to the people who have demonstrated that they are flight worthy and have the aptitude required to do so, consistently. Even if they become glorified bus drivers in the end (as my cousin sarcastically calls himself, when he pilots for his company). Car driving in England nowadays is seen as a "right"... when it isn't. It is a privilege. Flying a plane with nearly 800 people on board, is an even larger privilege.