Blacklist
Another mechanism that FTA can enforce to penalize aggressors is the Blacklist. This is an automated system that records characters who take aggressive actions toward FTA or against other players in FTA L-points.
When a character performs an aggressive action, a record for them is entered into the blacklist. The record will specify a "penalty fee" and a "penalty multiplier", which vary depending on the severity of the action (e.g. more severe for destroying a Gate than a Network Node, more severe for destorying a Heavy Gate than for destroying a Mini Gate).
That character will still be able to use the FTA, but will now pay the base fee multiplied by the "penalty multiplier", and will continue to pay this higher rate until their total penalty payments have reached the "penalty fee" total. For example, if a character destroys an FTA Heavy Gate, they may receive a penalty fee of 5 EVE tokens and a penalty multiplier of 8; that character will then pay 8 times the normal fee to use FTA gates until their total penalty payments have reached 5 EVE tokens.
Characters can have multiple blacklist records. Each record will remain until the penalty fee for that record has been paid off, at which point the penalty multiplier for that record will no longer be applied.
This system discourages aggression against the FTA, but still allows players to take extreme action in emergency scenarios (e.g. destroying an FTA gate that is enabling an attacking fleet in your tribe's home system).
The blacklist implementation can be seen here.