This single trademark (TM) scammer victimized 2,900 people. His sentencing serves as a reminder to all those filing federal TM applications to be aware of phony e-mails from official-sounding organizations about alleged USPTO fees due regarding some aspect of your TM application or registration. As an attorney who has filed TM applications on behalf of clients, I've even received some of these e-mails myself.
To all those who've used an attorney to handle the filing and prosecution of your federal TM application (a wise move!), any communication about paying USPTO fees should come from your attorney. Beware of reminder/payment communications issuing from anyone other than counsel or the USPTO.