In addition to the security and privacy of your coins, there are other concerns about Bitcoin's stability and security that deserve our attention.
What can an organization do to make Bitcoin useless?
To end the Internet
How to shut down the internet? Aside from the high level of cooperation that would be required from private companies and governments, we don't know how to actually shut down the internet. The network was designed in part to continue even after a nuclear strike. The internet itself is also extremely resilient to attack, and information would simply be routed to any part we shut down.
Destroy all nodes and miners
Its network consists of individuals, groups, and organizations that run Bitcoin software on their laptops, phones, and tablets. Some of these participants buy equipment exclusively for this purpose. There are several miners that operate in the open and not behind a VPN , so someone could disable them. But since this cryptocurrency has a way to actually give someone money, usually through malicious means (ransomware), it will still find a way to operate on underground networks (Tor).
Make Bitcoin illegal
If a state made Bitcoin illegal, it would become much more difficult for people to buy it, exchange it for paper money, or accept it as payment in a store.
To make the Bitcoin blockchain unusable
The only realistic but extremely difficult way to stop Bitcoin and make it useless is to participate in its network yourself and operate maliciously from there.
Its structure is made so that anyone can participate anonymously as long as they simply comply with the rules of the Bitcoin software they will be using. For example, no rule says that blocks must be filled with legit transactions, so a miner could theoretically create empty blocks which, as they increase, will make the cryptocurrency weaker.
In the link below you can see a report from the University of Massachusetts based on a protocol adopted by Bitcoin's founder, Satoshi Nakamoto
https://arxiv.org/pdf/1701.03977.pdf
