It makes a big boom and pretty explosion. Isn't thats enough of a reason!

Heres a basic explanation about the mechanics of the game, what the video entails and what it takes to do that.

POS are like forward bases. You can hide behind its shields and let its defenses attack anyone who comes close. You can rearm, change ships, repair, and so on as well as industrial reasons such as mining and refining.

In 0.0 security space (no law and alliances can claim it through POS placements) you can make a lot more ISK (money) than empire but its more risky as there are no authorities. We claim an area of space which we run operations to protect to ensure we can make ISK there. These guys were free-riding and making ISK in our area while not contributing to the security of the area. So they had to be removed, we regularly attacked there ships and haulers but sometimes they manage to reach there POS to hide at it.

Taking down a POS is no easy thing, its a major problem in the game infact at the minute due to the firepower of a POS and mixed with a big alliance defending it with ships it takes a huge force (like the 3:1 ratio put on attacking in tench warfare) which sometimes due to pure number of players the EVE servers can't take causing lag in the system+area. The game runs on multiple servers/nodes which different systems run on, the busiest systems get more resouces on the servers so when a major conflict occurs in a normally quiet system it can't cope even though the servers assign resources depending on its level activity.

GJ to the guys who participated.