A method comprising: causing computer implementation of the at least one virtual boundary in a monitoring space corresponding to a monitored scene space; processing sensor data to generate a response event when there is, relative to the at least one virtual boundary, a change in a portion of the monitored scene space; recognizing a first hand gesture relating to a first hand of a user in the monitored scene space and in response to recognizing the first hand gesture in the monitored scene space in relation to a portion of the virtual boundary enabling user location of the portion of the implemented computer-implemented virtual boundary and recognizing a second hand gesture relating to a second hand of the user in the monitored scene space and in response to recognizing the second hand gesture in the monitored scene space performing a command relating to a user located portion of the computer-implemented virtual boundary.
