As many commenters here say, it isn't inherently more secure than a US-based service. It may be more socially secure, if the warrant system in Germany is more specific than our general system of warrants to spy on everyone foreign or domestic.

However, there's a good reason for German citizens to prefer German services: it takes money away from American service. Money is the only voice that will ever fix this.

So I ask every non-US citizen: please, take your money elsewhere. Please.