It's built as an affinity group builder. You're the one doing the networking, not the website. It only shares your information in a small group, not en masse. It's very smart really, building webs of trust.
There's still the risk of the government getting their hands on the actual servers and getting the data from there. They managed to do it to Mega Upload, and they were based in HK/NZ. (Though obviously the cases are very different.) While it may sound tin-foil-hattish to say this, the US government has demonstrated through Assange's legal persecution that they see WikiLeaks as an enemy, and I can easily see them trying to infiltrate the servers or even seize them outright on some cooked-up charge. Not to mention all the other governments out there who would love to have a list of names of revolutionaries.
If you've got nothing to hide, you've got nothing to fear. Supporting Wikileaks is not illegal. Freedom of speech still exists. The rule of law is still supreme. Stop being paranoid. Otherwise your paranoia will become reality.
I'm not one for tinfoil hats either, but I don't think it's so simple. There are a number of individuals who are detained on suspicion alone.
The example that jumps to mind for me would be: http://en.wikipedia.org/wiki/Maher_Arar
He was a Canadian citizen, detained in the United States, and deported to Syria where he was tortured.
I guess you missed the bit where it says: "He received C$10.5 million and prime minister Stephen Harper formally apologized to Arar for Canada's role in his "terrible ordeal" .[9][10]"
Sure, money doesn't necessarily negate a wrong completely, but this case is a good example to illustrate that the rule of law is supreme.
Moreover, I think there is a massive difference between Alquaeda related suspicions, etc, and other activities. I think they are considered to be enemy soldiers, therefore different standards apply.
The ultimate point is, you shouldn't be scared from your own government. You live in a country where the rule of law reigns supreme and your freedom is protected by the constitution. No need to self-censor, or be paranoid.
Awarded by the Canadian govt, not the U.S. The United States still admits no wrong-doing.
According to the linked article, "The Syrian government now says that Arar is 'completely innocent.'" (And as you say, the Canadian govt apologized and awarded him damages.) And yet he still has not had his day in a U.S. court, which is the jurisdiction that violated his human rights.
The United States govt can decide to have you tortured for a year, based on suspicion alone (no trial, no judge, no lawyer), and then afterwords, you cannot even complain in a U.S. courtroom about your mis-treatment.
EDIT: my bad, it looks like the US Court of Appeals actually heard the case in 2008. And then dismissed it.