I was browsing a website, and stumbled across a sample scheme for password-protecting web pages.  The owner of the website specifically had a page that invited people to attempt to hack it.

I wanted to give it a try, so I wrote up a quick python script a few hours ago to try brute-forcing the password.  (Which, in retrospect, was a stupid idea).

I left the script running for a few hours, but came back to find that my script was running haywire and the website was returning '509 Bandwidth limit exceeded' errors on all its pages.  ([EDIT]: I also checked via 3g on my phone, and using a school computer, so I know it's not limited to just my ip address)

This is not something I had intended to do, and feel really, really bad about it.

Should I send an email apologizing and offering to pay reparations?
Or am I just unnecessarily worried, and should let this blow over?

(I'm also not sure where in stackexchange to ask this question, but I think it might fit here).

[UPDATE]:
I sent an email apologizing -- once the site owner responds, I'll update this post.

[UPDATE]:
Well, it's been several days now.  The website is still down and the owner hasn't responded yet.  I originally wanted to wait for a response first before accepting an answer, but it might be a while, so I'll pick an answer.

First off, let me say this: I respect the ethics of anyone who would ask this kind of question (rather than just closing their eyes, walking away, and forgetting the whole thing).  My compliments to you.

Ultimately, this is a matter of personal ethics, so it is hard to give advice.  You need to do what you feel is right.

That said, your suggestion to try contacting the site owner seems reasonable to me.  I suspect that any harm done will be minor or that the cost will be minor.  Normally, the cost of bandwidth is pretty modest, in monetary terms.  But the site owner might appreciate hearing that his/her site is unreachable, and appreciate the apology.  But it's up to you, and what feels right to you.
