Islam doesn't just hijack planes, it hijacks the things that mean something to people. The great cities of the world are littered with relics of the Muslim occupation of their sacred places. Jerusalem, Delhi, Constantinople and Alexandria all testify to the Muslim predilection for taking over other people's sacred places, and turning them into mosques. It wasn't enough for Muslims to conquer Jerusalem and subjugate its inhabitants. No, they also had to take the holiest place in Judaism and build a mosque on top of it. Similarly it wasn't enough for them to conquer and rename Constantinople, they also had to turn the Hagia Sophia into a mosque. These are not exceptions to the rule. In Asia, the Middle East and Europe, there are numberless examples of the same thing.
To this day, Muslims continue seizing other people's places of worship and turning them into mosques. It's going on in Egypt today. It's going on in Yugoslavia where churches are being destroyed and turned into mosques, day by day. It's went on in Israel, in Joseph's Tomb, burial spot of the biblical Joseph, which was seized by Muslims in September of 2000, a year before 9/11.
Why do Muslims this? It's not just about seizing territory, though that is part of it. It's also about hijacking something more vital, identity. By Islamizing sacred sites, they also take control of other people's history and culture. As they have done throughout the world. Hijacking the Temple Mount, has allowed Muslims to claim Jerusalem as a holy city of theirs. Hijacking churches in Egypt and Yugoslavia, eliminates the religious history of non-Muslims from the area. Hijacking the Hagia Sophia, was part of the recreation of Constantinople, into Istanbul.