For those who put Adsense on your blog, I hope you have not missed out this post which explains what are click fraud and invalid clicks. I have bolded the parts where some publishers are guilty of committing without realizing it.
Anyway, I believe Google has eyes everywhere and you cannot escape if you commit any of the prohibited methods.
Some of my newbie friends asked if they can clear cookies and click on their own ads? The answer is NO! Google can track our IP and they know. So, forget about cheating if you wish to make money with Google Adsense.
Another mistake committed by bloggers is to whine about how pathetic their Adsense income is and this indirectly get the sympathies of their regular readers. So, with good intentions, these regular readers click on the ads every day and within a short time, Google will see a pattern and ban you as well.
One other thing is sharing of PC. Your family members or friends may unintentionally clicked on your ads. Or you little kids clicked it. That’s why I never allow my little kids to surf my own blogs.
Invalid clicks are clicks for which we decide not to charge our AdWords advertisers, since they may artificially drive up advertiser cost or publisher revenue. These include extraneous clicks without any value to the advertiser, such as the second click of a double-click. They also include many other types of clicks that we’ve determined aren’t motivated by genuine user interest.
“Invalid clicks” are often confused with “clicking on your own ads”. However, we’d like to stress that invalid clicks are generally any clicks that artificially inflate advertiser cost or publisher revenue, regardless of their source.
Click fraud is a subset of invalid clicks that are generated with malicious or fraudulent intent — in other words, clicks that are intended to drive up advertiser cost or publisher revenue artificially.
Sources for these clicks include, but are not limited to:
A publisher clicking on his own ads, or encouraging clicks on his ads
Users or family members clicking to support the site / publisher
Third-party programs with user incentives, such as paid-to-click services and click-exchanges
Automated clicking tools, robots, or other deceptive software
The same principles above apply to ad impressions and conversions as well. Some sources of invalid impressions include, but are not limited to:
Excessive page refreshes, generated either manually or automatically
Third-party programs with user incentives, such as paid-to-surf or auto-surf programs
Third-party programs for purchasing fixed amounts of traffic, e.g. “$10 for 1,000 page views”
As a reminder, any method that artificially generates clicks, impressions, or conversions is strictly prohibited by our program policies. You can also find more information about these topics in our Invalid Clicks FAQ.
Other useful related posts you may want to read are
‘What to do if your Adsense income spikes‘