Robots 2.1

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This is an Easy plugin to install and setup. does its job well. I was amazed at the amount of bots there were.

Great tool for stopping some common scrapers, undesired bots and such. Its one of the many tools in my arsenal against bots and I highly recommend it.
This is excellent and should be core for xenForo. Bad bots can be a huge resource hog eating up bandwidth and slowing your site down for nothing gained. This add-on installs in no time and works right out of the box! This is yet another one of his brilliant add-ons that should be included in the core of xenForo. Thank you Andy!
This is really quite an interesting, and yet novel approach to discourage unwanted robots away from your forums.(i.e. Feed them Blank pages!)

Remember to set the User Group Permissions to 'Allow' for both the Unregistered/Unconfirmed & Registered groups so the add-on can function properly.