Microsoft has explained that they have removed more than 1500 apps from the store.

Every app store finds its own balance between app quality and choice, which in turn opens the door to people trying to game the system with misleading titles or descriptions. Our approach has long been to create and enforce strong but transparent policies to govern our certification and store experience. Earlier this year we heard loud and clear that people were finding it more difficult to find the apps they were searching for; often having to sort through lists of apps with confusing or misleading titles.

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This process is continuing as we work to be as thorough and transparent as possible in our review. Most of the developers behind apps that are found to violate our policies have good intentions and agree to make the necessary changes when notified. Others have been less receptive, causing us to remove more than 1,500 apps as part of this review so far (as always we will gladly refund the cost of an app that is downloaded as a result of an erroneous title or description).