Image: A cesspit with an open iron gate.
Athena flaunts here shield, Aegis, and summon forth a violent windstorm that slams into the gate and force it open with brute force. You jump into the stinking cesspit, swim across it, carefully entering the gate and into the lower part of the caste dungeon.
There are a number of different types of automated attacks that attackers can use to try and compromise user accounts. The most common types are listed below:
Different protection mechanisms can be implemented to protect against these attacks. In many cases, these defenses do not provide complete protection, but when a number of them are implemented in a defense-in-depth approach, a reasonable level of protection can be achieved. See Authentication Cheat Sheet for more information on how to protect against automated attacks.
You may mistakingly assume that you don't need to protect against brute force attacks due to the fact that your login and locks are hidden, inaccessible or in this case, protected by a stinking cesspit, but a good hacker always find his way around these type of barriers.