I recall viewing once in the AdWords interface a report of all the clicks I'd received, and there were more there than what I was charged for. I concluded that Google is good at detecting fraud and is aggressive about not charging for fraudulent clicks. It's been a long time since I saw that report. I don't remember how to get to it, or if it is still one of the report options.

get alerts from Google when they have not counted specific clicks

No way that I've heard of. The frequency of fraudulent clicks is too high. You'd get alerts constantly.

Searching your website access logs, you'll find it is easy to see when a referral comes from one of your AdWords ads. You can compare the number of those referrals against what you are charged for by Google.

You can get all you mentioned by setting up various reports in the reports section with e-mail alerts. I advise geographic also. From monitoring it you will be charged for two sometimes three clicks from the same IP even in quick sucession. If the IP address becomes a problem you can block the address.

Ok, I see it. No point posting URLs because they're all inside the AdWords interface, but from the Reporting tab, at Create Report, there is a link "Learn more about report types". The landing page, I think, had a link in the upper right "Recommended articles" section called "Invalid Clicks report", which describes how to create that report. One of the "Recommended articles" on that page is "How does Google detect invalid clicks?", possibly of interest. There appears to be a mechanism by which they sometimes refund for invalid clicks up to 2 months after they've been charged, if they discover them late.

Back on the Create Report page, at the bottom, is the place to say you want the report emailed to you.

Hey thanks for your good info. I'll do this right away. Cheers

pavlovapete, one quick aside:

If and when you get to the point of blocking IPs, do be aware that it very possible for different users be coming from the same IP address.

AWA

The report you can run is a campaign report. When you choose the report you can then choose invalid click information.

If you see the invalid click options disabled, then make sure you unselect items like impression share and conversion data as you can't see all of that data in the same report.

Be very careful blocking IPs. I've seen people block entire companies because all the users were sharing an IP off a VPS, or accidently block entire countries (or even most AOL users).

You can often just search for an IP address to learn who the owner of that IP is (usually not people - but ISPs, companies VPNs, etc).

Thank you AWA and ewhisper for your advices.

Cheers

Of course three clicks in three minutes is not necessarily fraudulent. I regularly see multiple clicks like that from the SERPS (I am not currently running an Adwords campaign).