Can my employer viedotape activities or conversations in my office without my knowledge?

While I cannot give a direct answer to your question as I am not able to locate any law directly on point, employees do have a right to privacy in the workplace under both common law and public policy.  One of the leading NJ commentators on employment law (Rosemary Alito) notes that the extent of the public policy is not clearly defined, but is determined by balancing the employee's individual right to privacy with the competing public interest.  Other factors to be considered in the analysis are the extent of the intrusion and its effect on employee dignity; the existence of advance notice to employees of the possibility of the intrusion, how it will be done and how the results will be used; limitation of the intrusion to the extent actually required to satisfy the employer's legitimate purposes; and nondisclosure of private information obtained except for the the necessary and legitimate purposes of the intrusion. There is also a common law tort of unreasonable intrusion on seclusion, which essentially holds the intruder liable to the victim if the intrusion would be highly offensive to a reasonable person. Workplace searches are permissible, subject to the requirement of reasonableness and the expectation of privacy. Email and internet use is not subject to the same considerations of  privacy and the facilities are the employers property and subject to the employer's monitoring,  There are privacy considerations and purely personal or privileged uses, not inconsistent with the employer's policies of use, may not be properly monitored. The law in NJ is not clear, as noted, and NJ lawyers tend to look to other jurisdictions for guidance.  Depending on which side of an issue one is on, one can find support for both sides of the argument. Mike Warshaw