Links for Thursday February 28^th, 2008

• Nearly a million users, and no spam or trolls - RussellBeattie.com: An interesting look at how the "public IM" utility Twitter has kept itself (mostly) free of SPAM and trolls.

• Apple COO Discusses iPhone Exclusivity, SDK, and Unlocking - Mac Rumors: More complete notes of Tim Cook's talk yesterday, including a link to a quicktime stream of the entire talk.

• The Rise of the 'Citizen Paparazzi' - WSJ.com: Crowdsourcing comes to Paparazzi. Money quote: "What's more, they [professional paparazzi] gripe about rude and particularly aggressive behavior from some of the amateurs – no small allegation in an industry long known for its anything-goes tactics."