That's up to your ISP. If you do like I do, upload a page and don't link it and only share it with a particular person, you are safe from the majority of surfers. If someone wants to hack in and see what your web file directory is, then they have to use a port and go in with some other sort of software. Your ISP can protect against that. That said, there are ingenious hackers out there who can even hack a buffer. So, one thing to keep in mind is practicality. Who would want to target you and put in that much effort? If you upload, email or phone call your buddy, then delete, you're probably safer than you realize. The odds of a home breakin are greater than a random hacker getting your stuff in a quick upload/delete in my opinion.