Self-styled ‘uncarrier’ T-Mobile US scrapped data overage penalties on all its consumer plans. CEO John Legere then called on bigger rivals to do the same and launched an online petition to back his campaign.

“Today I’m laying down a challenge to AT&T, Verizon and Sprint to join T-Mobile in ending these outrageous overage penalties for all consumers, because it’s the right thing to do,” he said.

According to figures cited by T-Mobile US, more than 20 million Americans were hit with overage charges in 2013. And the penalties doled out by the three biggest mobile operators – when customers exceeded their data plan limits – topped $1 billion.

The overage announcement is the last in a three-day blitz of ‘uncarrier’ initiatives by T-Mobile US, which began with the unveiling of the Simple Starter plan aimed at 4G entry-level users (and which has no data overage charges).

Last year, T-Mobile US abolished annual service contracts and began phasing out overage charges with the launch of Simple Choice.

“Charging overage fees is a greedy, predatory practice that needs to go,” said Legere. “Starting in May for bills arriving in June – regardless of whether you’re on Simple Choice, Simple Starter or an older plan – we’re abolishing overages for good. Period.”

(Legere tweeted later in the day that the petition was attracting around 1,000 signatures per hour.)