Playing (tampering) with Bitcoin is extremely difficult, even though it is definitely public, more precisely because Bitcoin is completely public. A bitcoin has no physical assets, so you can't protect it by locking it in a safe or burying it within a piece of soil. In theory; all a thief needs to do to steal bitcoins from you is to add a line to the ledger that means "You paid me for everything you have". Another concern with this is double spending. If a bad actor can spend some bitcoin, then spend the same amount again, confidence in the value of the currency will evaporate quickly. However, for the bad actor to spend double, his account must control %51 of Bitcoin’s mining power. The larger the Bitcoin network, the astronomical and extremely expensive computing power needed. Hence, this is not considered a realistic conspiracy theory. We need trust to avoid any problems. In this case, the usual solutions would be to use traditional currencies and trade through a central, impartial arbitrator such as a bank. However, Bitcoin made this unnecessary. (Possibly Satoshi's original statement was published in October 2008, when trust in banks was multi-generational low, but this statement is a recurring theme in today's pandemic environment and the resulting rising debt of their governments.) In a central ledger, the network is controlled over by the presence of an authority. On the contrary, the bitcoin network is decentralized meaning that everyone is naturally working for the benefits of the others. For the system to work properly, nobody needs to know or trust each other specifically. Assuming everything works as intended, encrypted protocols allow each transaction block to be linked to the last block in a long, transparent and immutable chain.