Since little information is available in English, here are some points of clarification:
-The main charge was "aiding copyright violation". The decision of the court is mainly based on the fact that TPB did nothing to prevent it and that they in every way advertised that you could download copyrighted stuff on their site. The fact that this can be done with Google or any other search engine is beside the point according to the court. Google cooperates at least to a limited extent with copyright holders while TPB made a point of pissing them off.
- According to the court indifference to the possibility of the copyright violations occurring is not enough as an argument to let them off the hook. This is not so much a controversial point in the guilty verdict but a very controversial one when it comes to sentencing.
-According to Swedish law you can be found guilty of aiding even if the perpetrators of the main crime (i.e copyright violations) is unknown and the full extent of the crime is unknown as well.
-According to the court information provider neutrality as defined in among other things the EU's e-commerce law does not apply to TPB. Their main argument is that TPB was not a general service provider but a search service largely aimed at facilitating downloading copyrighted material.
-The most controversial point is the sentencing. The basic question is if the three specific persons could really be sentenced for crimes that they did not and could not have had information about (each individual download). The court's answer is yes and the reasoning behind it is fairly vague and general in nature. When it comes to the damages the reasoning is rather strange:
Basically they say the following: The industry claims X million Euros in directly lost profits. This is clearly absurd as not all who download would have actually bought the product in question. So we'll split the difference and put the damages to X/2. X/2 turned out to be 46 million Swedish crowns. (€5 million)
Apart from the questionable reasoning one should put into context that a premeditated murder will in Sweden cost you on average 5 years in prison and 100,000 (~€10.7k) crowns in damages to the relatives. So although the guilty verdict of the court may be reasonable, the sentencing is very extreme by Swedish standards. As a rule damages are never in the millions and the idea is that the guilty party should have a chance to actually pay them. The sentence of 46 million crowns in damages is simply outside any Swedish legal practice.