[Zahlmeister]

> your landlord can tell you tomorrow than the next time your contract is up to renewal (usually yearly), the price will be 2x the current one and if you don't like that you have to leave.

It all depends on your contract. Some contracts may put limits on rent increases in. Yes, in Germany there effectively is rent control that prevents a doubling of the rent within a year, but generally rents don't double within a year.

If those rent controls were good enough to satisfy the affected people, why are there protests and demands for additional laws for even more rent control in places like Berlin? Why is living in Munich so hard to afford? At what point does rent control start to "work"?

[ido]

It works, it's just not enough. It's still better than the situation in the US, UK, etc where there's even less (I remind you that the OP's argument was that rent control was a bad thing).