Sorry, you can't delete them because they are not in your name and you are not liable for them in any given law that can be proven. They are uploaded by "anonymous"! Any law against the file isn't something you are liable for. So there is nothing for you to worry about. The only thing that would possibly make you liable is advertising everywhere that you are the anonymous uploader.
More importantly, it can't be proven you were the original uploader, either.
Even registered users are never targets of any law or copyright acts, it's the site that gets the message to take down any subtitles by media, subtitling, broadcasting companies, etc, not the user themselves.
Ok then, I'm relieved, thank you. But can you delete them so I would upload them from my account? I made these subtitles a while ago and corrected some of the bad mistakes and misspellings there.