Offer your thoughts or opinion on the input financial query or topic using your financial background.

What legal action can Paypal take against me if I don't pay them and I have a negative balance?
Paypal can take exactly the same legal actions against you as any creditor could -- take you to court for wilful nonpayment of debt, sell your debt to a collections agency, or anything else a business would do with a deadbeat customer. But this is a legal question, and as such off topic here.