On Node 1, an agent can let the timer run down to zero to automatically secure a node. This, in theory, proves that the player is an agent, as a hacker who does this will automatically hack then node. Of course, those less experienced suggest that a hacker could just wait until the timer is low and then secure. It is for this reason that players will often request the ZZZ to show a player as AFK after a node is auto-secured.
This strategy is banned in the unofficial tournaments.