Infinity Train creator Owen Dennis revealed that writers were almost barred from presenting a flashback moment in which Amelia indulges in an illegal act of "phone phreaking," but the scene was allowed because modern technology no longer makes what she did possible.
Dennis tweeted a link to a video clip from the Season 1 episode "The Past Car", showing Amelia and Alrick at a pay telephone, with Amelia blowing a whistle into the phone mouthpiece. A narrator explains that the specific tone from the whistle "hijacks" the phone system, allowing the call through without payment.
Dennis wrote, "We almost weren't able to show Amelia doing this because it's for kids and it shows two people doing an illegal activity and the steps to do it. However, because phone lines are no longer analog and are all VOIP, it technically can't be done anymore, so we were able to show it!"
In a second tweet, Dennis explained, "Fun fact, the phone lines in the UK used a different system and weren't able to be hacked this way, so that's one of the reasons we had Amelia and Alrick move to the US for college."
Under analog phone systems, phone customers are charged by the minute and under some circumstances, such as international calling, for the distance between both parties to the call. So-called "phone phreaks" were among the earliest hackers, but using the whistle method to make free long-distance calls constitutes fraud.
The first three seasons of Infinity Train are available on HBO Max and Cartoon Network.
Source: Twitter