cash only

Using any third party processor or your bank,
you are very open to losing their service

problem is people (young idiots usually)
will just contact the processor or bank
and they make a fraud claim in an attempt for them to scam you
(most likely it would also be for a petty amount from a petty buyer)

once a report is made your account is automatically frozen/limited etc.
even taking their ID cannot prevent this,
you may be able to get account reopened
but thats always a maybe.