keyplyr - 5:00 am on Jul 15, 2012 (gmt 0)
I block all AppEngine-Google. In fact, I block anything app.
The thinking is - although I optimize my sites for mobile rendering and enjoy a large visitor base from various mobile devices, the app world is just as malicious and copyright infringed as the internet is in general.
Anyone can write an app for any reason and use AppEngine-Google or any other platform. Many social site scrapers and parasites have app based tools developed for mobile phones & tablets.
I've found my content on several social spin-off sites that publish to mobile apps. I'm convinced these social sites make deals with various interests to sell/lease content supplied by their users with or without the user's consent.
I've also caught mobile apps scraping my images for album art, wiki profile photos, event info, etc... so I block them all now, adding a few new ones each week it seems.