Anchors, embedded images, and all other elements which contain URIs as parameters may cause the URI to be dereferenced. In this case, the security considerations of the URI specification apply.
Documents may be constructed whose visible contents mislead the reader to follow a link to unsuitable or offensive material.
The MD attribute is useful when authors are concerned that a linked object may be subsequently changed to something other than intended. This attribute is used to specify a cryptographic checksum for the linked object to provide a check on its integrity.