I think maintainers would definitely love more some monetary support rather than just a thank you, specially those doing it in their free time (since some maintainers of big open source projects are well established paid employees).
I just wanted to know what bureaucratic hurdles one has to jump in Germany to even be able to receive donations on your webpage. I don't want to go into the gory details, but just come with something that I say for years very often: The surest way to become a terrorist very fast is to read up into law.
And this is only for being legally able to receive and not about the taxation issues that arise when you concretely receive donations.
Also in countries there are lots of preferred ways on the methods for money transfer. For example in Germany many people don't want to use a credit card and prefer SEPA money transfer/direct debit for paying in the internet.
Yes, of course one could use some fancy cryptocurrency, but the legal/taxation issues remain.
Unless of course, you say you are non profit - then they have to accept that, complicated, yes.
But if you want small donation money for a webpage, it is very easy. You register a small company for it (cost 20-30€, time 20 minutes at the finance agency. and you can use that company for many other similar things). And then you are legally good to receive money in all forms, bitcoins or not. They don't care how you got that money. All that matters to them is how much profit you made in a year. If it is below 16000€ you don't pay (company) taxes - and they totally ignore you for being not important. If you make higher income, well, then you start having a serious business, with taxation and probably more regulation, true.
But for small things I found it not so hard.
Which makes the tax declaration much more complicated. Additionally this can easily cause lots of trouble with the employment contract.
I mean sure, since I am a libertarian, I prefer there to be no hurdles and no taxes at all, but the majority of people think different. And you are not even a libertarian I suppose? So you just want a excemption from taxes/buerocracy for you? Or just for small things like donation? Yeah well, this is the case right now, but they need to somehow verify that it is indeed small. I found the current situation reasonable. A bit more effort with tax declaration, but not really much, having a small business.
"Additionally this can easily cause lots of trouble with the employment contract."
And this is a problem with your contract then, which you negotiated and nothing for which the state is responsible.
I am not against taxes per se, but I am a deep hater of bureacracy.
I paid a bug bounty to someone in Germany from Canada with Bitcoin. I guess I'm a terrorist now.
But I would wager that the receiver (accidentally!) did tax fraud, since the legal situation around taxation of Bitcoin payments in Germany is not really clear. I can nearly say for sure that if he is not a professional who specializes in international taxation laws (or at least has access to an expert in this area) he probably did a criminal act (which does not imply that he will be prosecuted etc.).
Also I would bet he did something wrong in the accounting of these donation (which can easily happen, since there are so many formal details to consider - do something wrong and you are in trouble). Again a source for big legal trouble. This will rarely be prosecuted, but is nearly always a sword of Damocles.