Its good to have a locking feature by default on the campaigns/workflows/web-apps or any other such activities on the platform which are already in editing mode by an user.
This is something you can do by yourself by adding
<sysFilter name="writeAccess"> <condition enabledIf="$(lockedBy)!=0" expr="FALSE"/></sysFilter>
Thanks Marcel for sharing this.
Yes, i was hoping to have something on similar lines - OOB for some most commonly used activities .