Should police hack?

Well, that's a good question. The topic came back to the surface after the discussion of the new German "anti-hacking" law. Apperently, F-Secure did a survey on this: Should police hack?

Out of the 1,020 respondents, 23% were in favor, 11% were undecided, and 65% were against. Approximately 70% of the responses were from one of five locations: Sweden, Germany, Great Britain, Finland, and the United States.

Over 91% of Germans were against such techniques, while only 56% of Britons were against them.

Considering the geopolitical factors and events such as the 2005 London bombings might explain the differences between these countries.

Well, the question is also, how will they "hack" the PC's? Through vulnerabilities? We should try to update everyone's system to protect them, not exploit them. Through (unknown) backdoors? Well, bad guys will also find these sooner or later. Through malware? But then, how will anti-virus vendors make the difference between good malware en bad malware? There are a lot of vendors and they are from different countries so German law doesn't apply here.
Also, as stated in the F-secure article, the amount of data collected in "Online house searches" could provide such quantities of data that it overwhelms the signal with noise. So this doesn't seem very effective. So should police hack? Give us your opinion.