Yes it is true. The approval of google adssense for our web site is really a challenge able task. The adsense team watching the content of our website minute to minute. The won't give approval or they will disapprove our site if any invalid click activity or posting copied content in our site. I also lost my adsense account with amount of $70 after working 6 months due to invalid click activity. Then I could not get new approval for account opening for the past one year. I got new adsense approval just last week only.
So, you have to take utmost care while creating and handling the google adsense account. you may create statcounter to watch the hit performance of your account. Best of Luck.