Kazaaa has nothing to do with torrents, but what do you mean by corrupted?
Torrenting can cause a fragmenting issue, but defragging clears that up. And like anywhere else, random executables sometimes contain malware but there's nothing inherent in torrents that makes that more likely.
I meant “file sharing” more generally not “torrents” specifically (I edited my previous comment). I don’t know what exactly happened to my computer but I suspect malware. While not inherent to torrents, it does seem inherent in sharing of random executables. Have the trust issues improved? What are some good use cases of torrents?
So while Kazaa and the like eventually got the ability to actually download from multiple sources, and be able to see that a particular source is popular, as I recall from the early 2000 days, back then it was pure point to point. That is, if you chose to download something, you also were implicitly choosing what source to download it from. So even if five people had the file "Foo", you chose which one to download, and there was no way to know that 4 had the same file "Foo", and 1 person had something else, with no way to know which was what you wanted.
Torrents avoid many of those issues; you can see how many seeds a file has (though Kazaa and the like later added that). And you had to have gotten the magnet link from somewhere, which would have its own evaluatable trust. It's the difference between downloading file called "Foo" from random internet user's computer, and going to a website, that you know, and downloading a file called "Foo" that you also know has been downloaded, and retained, by X number of users.
It's mostly like the rest of the web, though another commenter is right that seeds demonstrate a small amount of trust. If I'm on some random public warez site, my executable is likely to be malware. If I'm on something like the Internet Archive, Debian's site, or /r/datahoarder, their torrents are likely just a more efficient way to share data.
I don’t think torrents are any different in that aspect from the rest of the web.
Just as you would download and run an executable from a trusted source, you can download a torrent of an executable (from that trusted source) and run it.
E.g. many Linux distributions offer torrent links next to regular downloads; if you trust that website, you can download either file.
> . I don’t know what exactly happened to my computer but I suspect malware.
Yes, that's very plausible.
> Have the trust issues improved?
If you're retrieving executable code, the source giving you the magnet link is usually given some implicit trust. A good practice is to distribute a hash or better still a signature of the file(s). Though I would expect BitTorrent is designed to protect the shared contents' extents via hashes too.
If the content is some multimedia, then ideally it could be untrusted. Your favorite OS probably has much more robust libraries handling the multimedia content than it did a decade ago. But ultimately if the content distributed is infringing then it probably comes from a less trustworthy source. In which case you should have a different posture when handling these untrusted files than the generally untrusted interwebs content.
Torrenting can cause a fragmenting issue, but defragging clears that up. And like anywhere else, random executables sometimes contain malware but there's nothing inherent in torrents that makes that more likely.