except that in some case this private companies can change the rules of the game like happens whit etherium, who fork the blockhains after one of the biggest ow

except that in some case this private companies can change the rules of the game like happens whit etherium, who fork the blockhains after one of the biggest owner being theft for have an insecure smart contracts, and some Blockchain only allow certein type of transactions, o request specific fees for gambling for example.