Whatever you put on the permaweb cannot be deleted. The permaweb’s file storage method was created so that each data storage block cannot be removed by anyone – not you, not ArDrive, not Arweave (the creators of the permaweb), not the world’s best supercomputer.
Furthermore, the permaweb exists as a decentralized network. It distributes data to thousands of nodes which make it impossible for any centralized actor to remove the data from the whole network. A node may go offline, but the redundancy of the network keeps the entire repository of uploaded information available.
Therefore, with no delete button and a decentralized network, any public information posted on ArDrive cannot be taken down by a third party. This makes it censorship-resistant.
In November 2020, a government made a failed attempt to censor the permaweb. Read the story in Fortune Magazine