Description: On Apple OS X Mountain Lion (10.8), the error ""Minecraft" is damaged and can't be opened. You should move it to the trash" is received. This is caused by Apple's Gatekeeper software.
Solution: In System Preferences, select Security & Privacy and click the lock icon that reads "Click the lock to make changes.". Then set "Allow applications downloaded from: 'Mac App Store and identified developers'" to "Anywhere". Start Minecraft.app. Once running, if you'd like, you may reset Gatekeeper to "Mac App Store and identified developers". Alternatively, you can right-click Minecraft.app and select "Open". You'll be presented with a confirmation dialog. You only have to do this once; afterwards you'll be able to double-click and run Minecraft.app without the above steps.
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