Rule #1 for studying social culture: pay attention to the sex and drugs.
When it was reported that Orkut is being used as a drug networking tool in Brazil, my immediate response was duh.
I have interviewed subjects who distributed cocaine in Baltimore via Friendster. (To my knowledge, they were never caught which makes it different than the situation with Orkut.) Other subjects have told me ways to find drugs on Tribe.net and MySpace. Obviously, i am not willing to disclose how or who. But this is definitely not unique to Orkut nor to social networking in general. For example, in college, people used to buy drugs on eBay.
Give people the ability to distribute information and they will distribute drugs. Tis just as obvious as if you give people access to attractive people, they will date. So, i find it very entertaining that people get up in arms about this.