Why are face composites difficult to recognize?

Terms relating to user comments

1. This Agreement shall begin on the date hereof.
2. Certain parts of this website offer the opportunity for users to post and exchange opinions, information, material and data ('Comments') in areas of the website. F1000 does not screen, edit, publish or review Comments prior to their appearance on the website and Comments do not reflect the views or opinions of F1000, its agents or affiliates. Comments reflect the view and opinion of the person who posts such view or opinion. To the extent permitted by applicable laws F1000 shall not be responsible or liable for the Comments or for any loss cost, liability, damages or expenses caused and or suffered as a result of any use of and/or posting of and/or appearance of the Comments on this website.
3. F1000 reserves the right to monitor all Comments and to remove any Comments which it considers in its absolute discretion to be inappropriate, offensive or otherwise in breach of these Terms and Conditions.
4. You warrant and represent that:
   1. You are entitled to post the Comments on the website and have all necessary licenses and consents to do so;
   2. the Comments do not infringe any intellectual property right, including without limitation copyright, patent or trademark, or other proprietary right of any third party;
   3. the Comments do not contain any defamatory, libelous, offensive, indecent or otherwise unlawful material or material which is an invasion of privacy
   4. the Comments do not contain any contaminating or destructive features or devices such as viruses, time bombs or coding designed to interrupt, destroy or limit the functionality of this website or any of this website's user's computer equipment or software; and
   5. the Comments will not be used to solicit or promote business or custom or present commercial activities or unlawful activity.
5. You hereby grant to F1000 a non-exclusive royalty-free license to use, reproduce, edit and authorize others to use, reproduce and edit any of your Comments in any and all forms, formats or media.
6. You hereby agree to indemnify and keep indemnified F1000, its affiliates, contractors and agents from and against any and all losses (including without limitation direct, indirect and consequential loss), costs, claims, damages or expenses of whatever nature and howsoever caused arising directly or indirectly from any breach of these Terms and Conditions or arising from the Comments posted on this website or content contained in any email sent using the facilities provided by the website by you including without limitation as a result of any infringement of any intellectual property or other proprietary rights, libel, defamation, obscenity or the Comments being otherwise unlawful.