And I will claim this as a fake first post. #slashdot
There are simple ways to stop this. Whether Twitter does this is another matter.
This is the same as any other optimisation task (eg link farms for Page Rank). People will try ti and (eventually) Twitter will work-out how to clamp-down on it.
Rinse and repeat.
Why is this news?
http://www.insidefacebook.com/2010/10/15/as-source-for-current-facebook-employees-google-has-big-lead-on-yahoo-microsoft-oracle/ suggests there are 277 ex-Googlers at Facebook. (There are reduced numbers from other big tech employeres).
--stock options: Facebook is/was pre-IPO. If you want to get rich as an engineer you would work there. You will never get that rich at Google.
--freedom: Google is a large company and it is hard to get stuff done. Facebook is small.
--Google is perceived as no longer being the place where the best work.