Denial for these reasons …
One or more member states consider it a threat to the public
politics, internal security, public health as defined in article 2 (19)
of Regulation (EC) No 562/2006 (Schengen Borders Code) or the
international relations of one or more of the member states).
… means that you will need a lawyer specializing in EU law. Requesting advice from the Internet is a waste of time because the answers will be classified into one of four categories …
- Get a lawyer
- Do something stupid (forged passport or covert entry)
- Jingos complaints telling you and your species to stay where you are
- Stupid incoherent of random morons
People who have been listed as threats to the security of the area have a history that requires a long speech with a specialist and there are no other viable alternatives. The same reasoning applies to questions about the appeal of the decision. Attempting an appeal for this reason is dangerous and, in addition, runs the risk that all your things enter the public domain! See a qualified practitioner!
The professional is needed, even if the deadline for an appeal has elapsed. There are data protection laws and freedom of information laws that require local experience to navigate successfully. "Cleaning your name" is not a simple job.
Related answer: Schengen visa refusal: the justification of the purpose and conditions of the planned stay was not reliable
NOTE: To avoid the natural corollary, let's add that …
- The consulate has already told the Department of Homeland Security in
USA UU. that tries to mobilize;
- The consulate has already told the other members of Schengen;
- The consulate has informed its colonial missions abroad; Y
- The consulate has informed the United Kingdom that it is trying to mobilize.
and the United Kingdom in turn has informed the Republic of Ireland and the
Commonwealth members to put a high flag in their passport.
Update April 21, 2016
The questions of phoog (whom I thank) about the possibility that this refusal arises from an erroneous identity caused an email exchange with a specialist. The result is that this reason ("One or more member states consider it a threat to public policies …") means that they had a biometric impact or some other positive conclusive coincidence. It's not like the US flight ban list where people with the same names generate confusion. Instead, it means that that person (and no one else) is in problem and it won't be fixed in the short term. Therefore, the previous answer still applies. I am taking the advanced law course in Schengen this summer and I can add another update to this answer after that.
Also note that if they cannot obtain a positive and verifiable match, they will not use this motive; instead, they will use the rejection of the Schengen visa: the justification of the purpose and the conditions of the planned stay was not reliable
Related article on how to request your transcript of the Schengen Information System: How can I find out if someone is in the Schengen Information System (SIS)? Note: Even if you find wrong information in your transcript, you will still need a skilled professional to officially delete it and restore it to its original state.