some say safe CTR is around 5%, and if more of that, risk to be banned.. does 'acceptable' term made by Google or by our own sense? how if our CTR up to 30%? is going to be banned??
5% is ok and many pro users of dp disclosed that 10% CTR is always fine if you have good traffic but 30% is too high buddy . I can't say that you can get banned but yes Google team must be watching your each clicks closely . If someone clicked your ads several time than you can loose your accounts .
i dont think google will immidiatly ban you when you have a high CTR, they probably investigate your site. And then make a decision, to ban you or not.
don't worry even if you 100% CTR. I have a site which sometimes only gets 3 visit a days and if all of them click I have 100% ctr, is google going to ban me for that? Nope they are all legit visitors from search engines
I wouldn't worry too, my CTR has been over 20% for a year and a half now, and i have not been banned. As the others said, the most important is to have your site not breacking any rules, quality traffic, don't click on your ads, etc... and it will all be fine.
CTR doesn't matter to Google as long as the clicks are legit, and they have the tools on the backend to see what is and what is not legit. So there is nothing you can do other than play by the rules.