It's like this, Google has a amazing tracking system, where they monitor the way you behave around the pages where they have ads. Because they are able to know every single IP or USER that views the ads in a certain page, if you click on ads of people frequently on Hubpages and just bounce right off, Google know you are doing that, and if you keep doing it repeatedly, it might bring you some trouble. Because Google will know that your IP address is identified as a unique person that only clicks on ads constantly and is not bringing any benefits towards advertisers. Normally depending on the time you spend on the pages of the ads you clicked, Google won't even count your click, it will just be consider invalid. But be really careful. Also clicking on your own ads from different locations, also triggers a behavior towards your account that is not normal. A lot of people get banned from adsense because they don't know how Google tracks fraudulent clicks and activities. Just be safe and avoid bringing any attention towards you. The guys from Google have no mercy, and once you go Black(listed) you can't come back. There is no appeal .
Hope it helped out a little