This tactic, by the way, is
also being pursued by the US supposedly to track "terrorists."
http://news.bbc.co.uk/2/hi/europe/6683803.stmSniffer dogs can use the collected odours to pick out individuals
The German authorities are compiling a database of human scents to track down possible violent protesters at the G8 summit in June, local media report.
The method, once used by East Germany's secret police, the Stasi, involves collecting scent samples in advance from selected targets.
The scents are then passed to police equipped with sniffer dogs who can pick the individuals out amidst a crowd.
...According to German media reports, most of the odour-collecting happened in dawn raids on the homes of suspected troublemakers.
Those targeted say they had scent samples taken from their clothes and other belongings or directly from sweat on the palms of their hands.
...
Petra Pau, a politician with the opposition Left Party, described the move "as another step away from a democratic state of law toward a preventive security state".
"A state that adopts the methods of the East German Stasi, robs itself of every... legitimacy," she said in a statement.
...