[jbk]

It's not really "dangerous", it is just that you give a bit more information to FB/Twitter/$SocialCompany than you thought you would.

While, I usually logout of FB or Twitter, I have a few adblock rules to block them on other webpages. It works fairly well... If I want to like and share, I believe I can do it manually...

[kanak]

You could add the EasyPrivacy list ( http://easylist.adblockplus.org/en/ ) to your adblock subscription.

[jbk]

Many thanks, I didn't know about this one.

[yuhong]

One reason it can be dangerous is that not all of them use HTTPS. And hopefully you know what Firesheep is by now.

[lukejduncan]

From what I gathered in the article, logging out doesn't solve the problem. The cookie works if you've logged in anytime in the last month

[code_duck]

Also, Facebook uses a Flash LSO. You have to clear that to really be logged out.

[jbk]

I don't have Flash :D

[jbk]

Which is why I said that I used adblockplus rules for this.