As companies nationwide have felt the impact of drugs in the workplace, an increasing number are battling the problem through drug-free workplace policies, employee education, drug testing, employee assistance programs and even undercover drug busts. If your company has joined the war against drugs, make sure you understand the legal issues involved-especially if you're deciding whether to hire and fire based on drug tests. Make a wrong move and you can land in court, defending your company against charges of negligence, violation of privacy, ....