Are you talking about ETFs? If so, I was always asking myself the same question. There's an interesting article from Jameson Lopp which addresses this issue of the effect of IOUs on Bitcoin's soundness: https://blog.casa.io/securing-bitcoins-scarcity/
As for zakat, sadaqah etc. We're generally tought to give from what we love most. And for me it's Bitcoin that I attribute the greatest value to. So ... 🤷♂️
I meant everything that can taint coins due to traceability...
For the second question, I meant how would someone protect themselves from unjust arrest, imprisonment and legal action if they happen to send money to some individual or group a government does not like... the Palestinian resistance being one relevant example as they are labelled as terrorists by certain regimes.
Bitcoin appears to be great unless you spend it on something the government is not okay with. It appears to worse than fiat cash and even worse than bank transfer for such use cases.
