The most pressing concern is "how clearly people are informed that their involvement in this study is voluntary"?
Just think of the wonderful new applications, such as justifying the existance of the national DNA database. Police will no longer be limited to reaction, but will be able to launch pre-emptive strikes just like politicians.
Dawn raids to pick up every potential murderer and rapist, advanced shooting of all those flagged as extremist muslims, undeniable genetic proof that T.B took cash for honours (testing of OBE winners to reveal they aren't really of the right "status"). How happy the boys in blue will be!
Of course, with all these new arrests and prison overcrowding, the government shall be forced to build new prisons quickly. Wooden huts can be knocked up very quickly. Throw in some barbed wire and some machine gun towers for the authentic concentration camp feel and we're sorted.
When the camps are full of potential murderers, perhaps we can issue "special" I.D. cards to the remaining potential shoplifters. If HM Gov gets any bad press about it all, we can always invade Poland.