Control Through Computer Monitoring Managers at a New York City import-export company suspected that two employees were robbing it. Corporate Defense Strategies (CDS) of Maywood, New Jersey, advised the firm to install a software program that could secretly log every single strocke of the suspects' computer keys and send an encrypted e-mail report to CDS. Investigators revealed that the two employees were deleting orders from the corporate books after processing them, pocketing the revenues, and building their own comapny from within. The programme picket up on their plan to return to the office late one night the steal a large shipment of electronics. Ploice hid in the rafters of the firm's warehouse, and when the suspects entered, they were arrested. The pair was charged with embezzling $ 3 million over two and a half years, a sizable amount of revenue for a $ 25 million -a-year firm.
Source Hellriegel Don, Susan. E. Jackson and John W. Slocum Jr., Management : A competency based Approach, Thompson, 2002, chap. 19, p. 526
Exlpain why controlling sometimes become ineffective

Explanation

Controlling sometimes become ineffective because of the following reasons:
(i) Difficulty in setting quantitative standards Control system is effective when standards are defined in quantitative terms. But in some cases, like employee morale, job satisfaction, etc, it is not possible to set quantitative standards. In the absence of these standards, measurement and comparison becomes difficult.
(ii) Little control on external factors There are certain external factors like change in government policies, technological changes, competition, etc, which are beyond the control of the organisation. Thus, controlling such factors becomes difficult
(iii) Resistance from employees Employees often resist control as they consider it as restriction or boundation on their freedom. e.g. Employees might resist working under close supervision of CCTV's and cameras.
Costly affair Control is a costly affair as it involves a lot of expenditure, time and effort. A small firm cannot afford to install an expensive control system. The cost of control system should not exceed the benefits derived from it.