I know it might sound crazy...

[WinterMage]

... but since I'm not allow to post something like "Please click here" under AdSense block, am I allowed to write something like "PLEASE DON'T CLICK ON THIS AD!"... You know, by knowing human nature.... Would that be violation of TOC?
LOL please dont laugh :)

[MediaSpree]

Yes that would draw unneccesary attention to your ads and thus be a violation of the TOS as I understand them.

Use the Google Optimization tips page and you should have no problem getting users to click without resorting to devious methods!

[Rodney]

It's not too crazy of a question, it was asked not too long ago :)

Here's the previous thread with an answer by a Google employee (msg #24) saying not to do it:
[webmasterworld.com...]

[BeeDeeDubbleU]

And ASA said ...

As the consensus has determined, this would be considered drawing undue attention to the ads appearing on your site. Although we understand that by asking users NOT to click on your ads your intent is to discourage clicks, this language could inadvertently encourage users to click by drawing undue attention to the ads.

If you are worried about click attacks from a particular user occurring on your site, I recommend emailing AdSense as soon as you notice something odd in your reports.

[Alioc]

"PLEASE DON'T CLICK ON THIS AD!"

Using the same inverse psychology, would you like to try putting a large header on your site?

"DON'T VISIT MY WEBSITE AGAIN, NEVER EVER!"