I used to get badgered relentlessly by the US blood donation people (Red Cross?) when I worked there. Every single time I said (in an umistakeably British accent) "I take it you still don't take British blood" (for fear of CJD) and they said "Yes, sorry, we can't".
Yet a week or two later I'd get harassed again to do it (sometimes in person at work, sometimes on the phone, sometimes by post, sometimes by email).