It looks like an innocent bit of jargon has acquired a nasty ring
At least that seems to be the case with "fracking," an accepted abbreviation for the hydraulic fracturing used to recover natural gas. As the Philadelphia Inquirer explains:
The oil and gas industry is irked about what it calls mischaracterizations of fracking, not the least of which is how the word is spelled. In the trade press, it is frac.
But as the shale-gas boom took off, and the mainstream media took interest, the K got appended to frac to reduce the chance of mispronunciation. Otherwise, fracing might look as though it rhymes with racing.
The new spelling has an unfortunate resemblance to one of George Carlin's seven dirty words, providing anti-drilling activists with a bounty of double entendres.