What Blackstone says is quite correct, but in fact, you have to put a LOT of info down in order to be traceable through cross-correlating ordinary facts like weather, etc. Just be sure to leave out quite specific attributes that are only shared by a few people.

If you look in detail at the wikisposure site that Blackstone is probably alluding to, you'll see that most people written up there either:

1) became top pedophile activists or site administrators [information on whom is usually minimal but they tend at least to become listed by username], or
2) used the same distinctive username, email or other unique, google-able items for both bl and non-bl sites -- the latter revealing their real-life information.

One person I know may have been baited out of a personal photograph by an impostor using instant messenger chat. This was a mentally handicapped BL, though, and most people who have run into haters online have had little difficulty becoming appropriately suspicious... people asking for porno pics, incriminating statements and so on...

In fact, I would go so far as to say that most of the (never-arrested) people for whom significant info is available on these sites either have some significant mental health issues or were inexplicably careless with a distinctive online nick, basically outing themselves to anyone who could type into google.

But in any case, I do do as Blackstone mentions and use the Tor proxy network for all BL-related sites. This is an especially good time in history to load up Tor because the current add-on (Foxtor 0.7.3) that makes it compatible with the most recent Mozilla Firefox browser is actually working properly.

See http://www.torproject.org/ and https://addons.mozilla.org/en-US/firefox/addon/3606

The qualm Blackstone mentions about the terminal tor server* potentially revealing details to a spy is basically a problem for military or famous people who use Tor for unencrypted email, and insert sensitive or identifying information into the mail. Since anyone using Tor to post here would be posting the message openly anyways, no hazard arises from the administrator of the 4th tor server being able to read the same info off his/her own computer.