[germanier]

This is not true. Only articles 1 and 20 can't be changed. For the rest in between no such guarantee applies and they were changed a few times in the past. Though most likely restricting any of the freedoms severely would be ruled unconstitutional by the very first article.

[eru]

Of course, the constitution is just a piece of paper, and what's protecting the rights in practice is a political system (especially courts) that tries hard to keep them.

Most of the rights already come pre-holed with exceptions, though. And lots of them contradict each other. There's lots of leeway, to justify a very wide range of policies as different `tradeoffs' between the rights.