We're all familiar with Murphy's Law: If anything can go wrong, it will.
With the rise of the blogosphere, we have the original Godwin's Law: The longer an internet argument foes on, the closer we get to 100% probability that someone will make a comparison with Hitler.
There's also the better-known Revised Godwin's Law: When someone makes a comparison with Hitler, the argument is over and the person making the comparison has won lost.
And of course there's Cole's Law: Thinly Sliced Cabbage.
Below the fold are a few more rules based on my own observations.
The Somebody, Somewhere Rule: For every stupid, evil, stereotypical or stupid behavior available to humans, somebody somewhere has done it.
Tara's Corollary to the Somebody, Somewhere Rule: The fact that somebody somewhere has done it is not necessarily a cause for panic, legislation, or gross generalizations about that person's demographic group.
The next three were inspired by wacko homophobe Paul Cameron :
Cameron Rule #1: People are more easily suckered by crap with numbers in it than by garden-variety crap.
Cameron Rule #2: If you hear a "statistic" about GLBTI people that sounds unbelievable, it is, and the source is probably Paul Cameron.
Cameron Rule #3: Anyone using Paul Cameron as a source, is by definition a crap source.
Cameron Rule #1 was in response to Paul Cameron's infamous "obituary study," and other travesties of phony research, but it applies in any context. "Al Gore uses electricity," garners a shrug. "Al Gore's house uses 20 times as much electricity as the average house," sounds impressive and becomes an easily-repeated meme, even though it isn't true. Similarly, "Rahm Emanuel spoke with Blagojevich," sounds believable because it gives the false impression that someone actually counted these imaginary calls.
The Bigot's Rule: A defining characteristic of bigotry is that all members of a minority group are held responsible for the bad behavior of any one member of that group.
Someone else has probably already copyrighted an official version, but here's my Flaming Pie Rule: When a controversial topic peaks on dkos, 40% of diaries will be passionate posts about it, an additional 20% will be snarking on the passionate posts, and another 20% will add diaries on the topic to complain that there are too many diaries on the topic. (See? I made up numbers, and it works much better that way!)
Floor's open - what are the rules you've discovered?