So a couple of weeks ago a girl knocks on my door... Asks me if I have wifi. Told her I did and she asks if she could use it as her Internet got disconnected. I said yes and she gave 20$ in return for 2 weeks usage. So done...

A couple of days ago get home and find 20$ in the mailbox. A nice note thanking me and another 20$ for until the 1st of Sept. Yesterday connection was slow. So I decided to hang the key. I became a little worried that she'd be doing something malicious. Don't know why apart from connection being slow and not steady.

Now I'm feeling a little awkward about it. So my question is: is there a way to hide my network? And is there a reason to be suspicious? My ISP max bandwidth allowance but even if I exceed it the penalty's maximum fee is 40$ which I already got in return.