Consumer rights group Electronic Frontier Foundation (EFF) launched a new attack on T-Mobile US, accusing the operator of going against net neutrality principles with its new One “unlimited everything” subscription.

EFF, which earlier this year hit out at T-Mobile US’ video streaming service Binge On for similar reasons, told technology publication The Daily Dot it is still gathering information on the plan, unveiled last week, as it called into question T-Mobile US’ commitment to net neutrality.

While pitching the subscription as offering unlimited data, T-Mobile US said those using more than 26GB of data per month (approximately 3 per cent of customers) “may see their data traffic prioritised behind other users”.

Subscribers to the plan will also only be able to watch video in standard definition or 480p quality, unless they pay $25 extra to view video on higher quality.

“From what we’ve read, thus far it seems like T-Mobile’s new plan to charge its customers extra not to throttle video runs directly afoul of the principle of net neutrality,” EFF’s senior staff technologist, Jeremy Gillula, told the publication.

Gillula suggested that T-Mobile US’ plan to limit video streaming quality may also violate US regulator Federal Communications Commission’s Open Internet Order, which he said “explicity said that ISPs can’t throttle traffic based on its type, or charge customers more in order to avoid discriminatory throttling”.

T-Mobile CEO John Legere slammed EFF earlier this year after it said Binge On, which offered the company’s subscribers the ability to stream video without eating into their data caps at lower quality, also went against net neutrality principals.

After a foul mouthed tirade against the consumers rights group, Legere backtracked and issued an apology.