CAPTCHA, are you really online?
I was just considering the issue of people who always show up as being online for weeks on end, and realized that another far smaller game I play has dealt with this issue long ago, simply pop up a captcha every few hours and if the player fails to solve it within five minutes they go offline. Higher trophy levels and perhaps to a small extent town halls would see them more often. Players who repeatedly stay active for hours without collecting resources, donating troops, or attacking and then fail captchas would be banned.
If someone is really dedicated enough to stay near their iPad and tap the screen every few minutes for hours on end then surely they are dedicated enough to type in a few letters and numbers every so often. Perhaps at the really high levels or for suspicious players there could be more difficult captchas, so that if they always pass the regular ones but repeatedly fail the more complex ones even captcha beating programs could be caught.
I think this is something this game desperately needs, and I hope enough player support will show up to make sure the developers pay attention to this idea, so please add your support (or explain why you think this would be a bad idea).