What I'm curious about is future changes in user behavior in response to this kind of stuff. Private data, public data and the public-private grey areas like pseudonymous posts, access restricted (FB-like) profiles and such are getting leaked all the time. Paranoia is definitely building. Awareness of how exposed people are is building. Yet, exposure is going up not down. People are posting more stuff online. I wonde…
Polygamy is already the norm in the West, only it's serial polygamy instead of parallel one, i.e. you're supposed to dump your previous partner before picking the next one. But most people enter most relationships being very open to the idea that it won't be lifelong, and that other partners will be part of their sexual, sentimental and patrimonial future: this constitutes polygamy, irrespective of the order in which you have sex with the several partners you plan to have.
Will insistance on serial polygamy soften? I'd say that the forces seem aligned for this to happen:
* reproductive control was the main reason for historical control over people's sexuality. With reliable contraception and easy paternity tests, those incentives are dramatically weakened.
* don't underestimate homo sapiens' urge to practice polygamy: historically we've had to punish adultery by gruesome death, it still routinely causes financial ruin in the US, yet people always kept committing it! They're still willing to wreck their own children's family and well-being, in exchange for some renewal in their sentimental and sensual lives! This urge seems to me at least as strong as the gluttony epidemic, which turns many Westerners into impotent, morbidly obese wrecks, one hamburger at a time.
* Exposure accelerates acceptance. Internet is bound to make affairs more and more visible, and as a result, we'll get used to them.
As for modesty, even before Internet, the list of which body parts / positions were naughty evolved fast and flexibly, within decades (think miniskirts, sleeveless tops, bikini, monokini, Frei Korper Kultur, or conversely, the comeback of islamic female garbs in middle eastern countries). With Internet as a great accelerator, we'll soon be mildly too bored to Google sextapes of our acquaintances. I known I already feel that way about celebrities. First time patrons of naturist resorts typically report nudity-induced awkwardness to last about 1/4h :-)