How should European countries react on the NSA activities?

[a completely inoffensive name]

Because helping Russia might encourage a degeneration in the US. We would be rewarding Russia for being a much worse place while facilitating Russian geo-political goals which are even more mercenary than American ones.

Refuse to deal with the US, perhaps, but don't cleave to Russia instead.

Maybe the rest of Europe should back Germany to become a Great Power again?

After all, why not?

You will need to properly flesh out that first statement there. A handful of activists over the past few years have embarrassed the US, under the guise that the US government has abandoned its principles and the Constitution. And thus the US government will proceed to become Russia 2.0 even faster?