Drugs and Alcohol together form by far the most common catalysts for a criminal offence.

The Local Courts are packed everyday with persons who have been charged with either driving whilst under the influence of alcohol, or have committed acts they would never have committed had they not been under the influence.

Our society's is continuing obsession with the criminalisation of drug possession means that there is a constant stream of persons before the court for possession of drugs. This is especially so at this time of year with various music festivals in full swing.

It has become a very common sight at these music festivals to see Police moving around with sniffer dogs.

The process is that Police attend these events with a warrant allowing them to perform the surveillance activities. If a sniffer dog gives an indication, usually by sitting next to a person, then Police are able to search that person for any illicit substances.

The statistics show that thousands upon thousands of people are charged every year with drug possession as a result of these searches. However, recent figures released by the State Government showed that approximately 80% of the searches revealed no illegal substances on the person's body.

Both Greens Upper House Member David Shoebridge and NSW Council for Civil Liberties Secretary Stephen Blanks have argued that the use of sniffer dogs should be ceased in the light of these adverse figures.

Police have responded by indicating that frequently persons who are searched but no drugs in their possession admit having previously handled the drugs, which is no doubt the reason that the dogs have identified them for searching.

The questions remains however whether it is appropriate for people to be subject to pat down searches when the initial indication used to justify the search is so inaccurate.

There must, in these circumstances, be a balancing act between a person’s right to go about the business without being subject to Police search and the need for Police to enforce the laws against drug possession.

There is of course a compelling and important argument for why drug possession should not be illegal in the first place. But in circumstances where it is illegal, it becomes a question of whether the infringement upon our personal liberties is justified in the circumstances.

It should further be noted that whilst some people are subject only to pat downs and, if nothing is found, are allowed to go in their way, others are subjected to strip searches and, in certain cases, even more intrusive examinations.

Police may well be basing the decision whether to conduct these more intrusive searches upon their impressions of the person, but the question is whether it appropriate that people be searched based merely upon a dogs clearly imperfect ability to detect drugs and a Police "hunch" as to the likelihood of drugs being concealed on that person.

Another issue is that there can be no denying that the offence is extremely prevalent in our community. Thousands upon thousands of people commit the offence of possessing illegal drugs every weekend, and Police would be justified in arguing that they need as many tools as possible at their disposal in order to fight the extraordinary level of offending.

There are further deterrent effects for a persons who would otherwise take such drugs in knowing that sniffer dogs are frequently present at these events and they are likely to be caught.

Like many things, this matter ultimately comes down to balancing exercise.

It may be that in the light of these new revelations there is some scaling back of Police powers in relation to these matters, or else hopefully some new training or a technique that can be used to minimise the concerning number of false positives.

It appears that the Greens will be targeting this issue into the future and it will be interesting to see what if any changes eventuate.