Everchanging Cycles viz. the Trojan Horse, from Pete Earle
In the last week or so, I've been tricked on several occasions into opening junk mail that I'd ordinarily have detected and discarded unblinkingly.
The ruse? The advertisements/solicitations/etc. arrived in my mailbox in pen scrawled, hand-addressed, regularly-stamped envelopes. Inside, though, was the full come-on.
Not bad.