not sure what you mean, if you mean how do they track down abusers, like other 1st tiers they log ALL IP traffic for a certain period of time. When you report abuse you must give a precise timestamp with the log containing the person's IP (So keeping your clock updated hourly with NTP is a very good idea). They then check your log against theirs and check the persons IP against the login records to tell them who had that IP at the time and then they have your account name which they pass onto the second tier ISP that owns the account who then contact the person in question.
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