[delinka]

This kind of article reminds me of bad PDF redaction and then the redactor being surprised that people can still read the redaction.

You don't stick text where a computer can read it and then marvel that the computer can read it. And if you want something truly hidden, you don't publish it.

If you're worried about Google's index, they'll obey robots.txt. Alternatively, customize your reply when you get the Googlebot user agent.

[JonnieCache]

"Alternatively, customize your reply when you get the Googlebot user agent."

WARNING: BE VERY CAREFUL DOING THIS!

This is one of the main ways that the googlebot detects spam/malware sites and doing it can utterly destroy your ranking forever in some circumstances.

[pork]

You're missing the point -- the site owners probably WANT that content to be indexed, but traditional spam protection measures have included (in the foggy past) not indexing the contents of hidden elements. BMW Germany famously stuffed a hidden DIV full of spammy keywords.