One area where IPFS improves on HTTP is in allowing comprehensive auditing of stored data. For example, thanks to its content-addressing functionality and, in particular, to the use of unique and permanent content identifiers, IPFS makes it easier to determine whether certain content is present on the network, and which nodes are storing it. Moreover, IPFS makes it trivial for users to decide what content they distribute and what content they stop distributing (by merely deleting it from their machines)."
But if you run just a node, everything that is on the node is there because either you have added it or you have explicitly requested it.
IPFS is not like freenet or other systems that shard data over all participants.
This obviously hasn't been the case for bittorrent, so I don't know why you would assume that would be the case for IPFS. Even ignoring the legal risk of blindly re-hosting whatever illegal bootleg-ISIS-child-porn-malware.exe on the net, the use of a blacklist isn't sybil proof so you just get bogged down with spam by the first attacker and run out of disk space.
I'm not sure how you are imagining IPFS works.
You don't add them manually, its just when you open up a link in your browser or video player, it gets stored for some amount of time and seeded before perhaps being pruned or kept forever depending on the users preference. You don't have any issues with unknowingly hosting illegal files this way.