The tool would have allowed individuals to check whether an Apple device they planned to purchase was still locked or not. All they needed was to get hold of the serial number of the device before using the Check Activation Lock tool available on iCloud.com. Once the result shows that the device was still locked, it would likely mean that it was stolen or lost. At the same time, sellers who refused to give out the serial number of the Apple product they were selling could lead to speculation.
When you visit the iCloud page where the tool is available, your browser will redirect you to a 404 error or a "Not Found" page; rendering it unusable. Other users were able to notice that Apple had earlier removed its reference to the tool found on a Find My iPhone support document.
Apple's decision to remove the tool comes as a surprise to everyone in the community, especially since a lot of people relied on it as protection for their device in the event that it gets lost or stolen. Since Activation Lock automatically gets enabled upon turning on Find My iPhone, Apple users did not have to worry about adding the security themselves. With the Activation Lock enabled, an Apple device cannot be used without the right owner's Apple ID and password; even if the device has already been erased or reactivated.
When asked to leave a comment about deactivating the tool, Apple did not respond right away. Currently, we're still waiting until Apple lets us know the reason why the Activation Lock status checker tool is no longer available.