Well now, it depends. If I let someone use something of mine that is licensed and restricted by the government because of the potential for misuse, such as a gun or prescription medication, then I am responsible inasmuch as I helped them circumvent government licensing.

If I lend someone an easily obtainable item such as a pencil sharpener or a cat, and they commit a crime using it, I don't see how I'm responsible.

The question is which of those categories Internet access falls into.