Hormel has made it clear that they *do*not*object* to the use of 'spam' to refer to junk e-mail. They do maintain a proprietary interest in 'SPAM' and people who use the all-caps form to refer to junk email have gotten 'cease and desist' requests.
OTOH, the Monty Python skit -- from which the e-mail usage derives -- did use the word as referent to the "spiced ham" product, and Hormel did not have any problems with _that_.
It has given Hormel *millions* (literally!) of dollars of free publicity for the product.
And introduced it to a whole new generation -- too young to be familiar with Monty Python's diner.
Sales have actually increased slightly, but not enough to support any claim of cause-and-effect.
Not necessarily 3x daily, every day, but often enough to *seem* like it ;)
It was -- fortunately, or unfortunately, depending on your viewpoint -- about the only meat product that could/would survive _all_ the conditions encountered in shipping food rations to the front lines. The length of time it took to get food to the front, and the lack of means to keep things cold, meant that other products spoiled and/or went rancid.
That is *WIDELY* variable -- depending on the species. The one frequently kept as a pet is a South-East Asian breed -- the Vietnamese Pot-Bellied Pig. A *distant* cousin of the animals used in the U.S and Europe for feed animals.
Many U.S./European varieties are 'temperamental', to put it charitably, and a wise person exercises considerable care around them, particularly when feeding.
In large part, I suspect, with the 'nice' pigs, it is a matter of 'socialization' with humans, starting from a very young age.
Wild pigs are notoriously aggressive/dangerous -- especially when 'cornered' (as with any other wild animal). Do a literature search for references to a "wild boar', and being gored by same, With their tendencies to root in garbage, carrion, etc, the tusks/teeth were a serious source of infection when injuries were inflicted.
With the exception of the law-enforcement-officer reference, all of the connotations mentioned _are_ directly based on representative behaviors of the typical American/European farm animal.
Popular because: Gasoline burns hotter. Gasoline has (somewhat) more energy per gallon. Gasoline was easily available, *everywhere*.
Discontinued because: Gasoline *very* volatile -- vaporizes at relatively low temperatures. *Explosive* concentration of vapors was too easily reached.
[TELECOM Digest Editor's Note: Regards 'PIG' and police officers or other municipal employees, do not forget how the City of Chicago and Illinois Bell were each greatly embarassed by having 312-744 (312-PIG) assigned to municipal offices -- including the police department -- in the middle 1960's by a witty phreak who happened to both work for Illinois Bell (until he got canned in a housecleaning the telco did a year or so later) and the Chicago Seed newspaper (until it went out of business once the Vietnam war ended.) PAT]