This is true even for a torrent btw. And (un?)fortunately you can distribute anything on IPFS as long as it's encrypted.
Select users who have the decryption key (communicated out-of-band) might be willing to pin the encrypted data for the benefit of others who also have the key. There are also for-pay pinning services who probably wouldn't care whether the data was encrypted. And whether it's pinned it or not, as long as it's downloaded the data remains available to be shared (at least until it's GC'd).