Is there a way I can turn off the function which shows how many people are online

On my shop the tables of the DB keeps on crashing and each time it is the who is online tables.

Code:
130807 14:51:17 [ERROR] /usr/libexec/mysqld: Table './pieter_direct/whos_online' is marked as crashed and should be repaired
130807 14:51:27 [ERROR] /usr/libexec/mysqld: Table './pieter_direct/whos_online' is marked as crashed and should be repaired
130807 14:51:30 [ERROR] /usr/libexec/mysqld: Table './pieter_direct/whos_online' is marked as crashed and should be repaired