It's like a torrent. You don't host data that you haven't accessed. For content to stay hosted on your computer forever you have to explicitly pin it.
The number of people hosting it is the number of people accessing it.
CloudFlare can't modify the files. On IPFS you request files by a hash. If they give you a file with a different hash you know they gave you the wrong file.
I think the point is that they're hosting an HTTP proxy to IPFS. Since you're accessing IPFS files over their proxy they can modify the response you receive, since at that point it's just like any other website.
> Since you're accessing IPFS files over their proxy they can modify the response you receive, since at that point it's just like any other website.
Correct, but gateways aren't intended to be final solutions. They're compromises targeted at increasing adoption. You wouldn't try and reinvent the internet - you'd make the interoperable where possible, such that adopters can still send normal links, etc.
The number of people hosting it is the number of people accessing it.
CloudFlare can't modify the files. On IPFS you request files by a hash. If they give you a file with a different hash you know they gave you the wrong file.