Email Filters
Working for an oil company meant a constant battle with the spam filters which,for some unknown reason, didn't like terms like "twelve inch pipe" (especially when combined with "drill"). Most were solved, but I could never get the filter to accept the term "hole expanders" which I was assured was perfectly legal, decent, honest and truthful in the industry.
Another story involves a manager in India who managed to send a set of (mindbleach still needed) VERY hairy images to the whole organisation list, not his intended recipient!