What if they made BTC illegal?

What if your country made BTC illegal - they could simply execute a search warrant on your residence and seize all your devices if they could make a strong case that you were in possession of it. Then they could seize your devices including all your storage devices and perhaps even your keys if you were stupid enough to write them down. Then they could also ban you from using any electronic devices pending trial or else you would lose your bail and freedom.

We know the governments do not like crypto. Lately I see more and more controls in place through the institutions we use - like our own banks are making it difficult to transfer to legal exchanges or they lock your account.

This is perhaps an extreme example - however it is possible.