Even though the roll out of 5G smartphones hasn’t begun, AT&T has decided to replace the 4G icon on select devices with a 5G E symbol in areas with support for AT&T’s fastest LTE technologies. AT&T has been widely criticized for its 5G E tactic, but there’s no indication that the company cares or is even the least bit interested in reversing course. The symbol has already started appearing on Android devices and just recently showed up on the latest iOS beta.

AT&T’s strategy, which arguably amounts to trickery, has been categorized by many as misleading at best and purposefully deceptive at worst. Consumers, though, aren’t the only ones taking umbrage with AT&T’s tactics. Yesterday afternoon, Sprint filed a lawsuit against AT&T over its 5G E sleight of hand.

According to a report from Engadget, Sprint accuses AT&T of engaging in a “deceptive 5G E campaign” designed to confuse and mislead customers into thinking they’re enjoying true 5G support. The end result, Sprint argues, provides AT&T with an unfair competitive advantage.

The lawsuit reads in part:

The significance of AT&T’s deception cannot be overstated. Following years of tremendous growth in both the number of data users and in the amount of data being consumed, consumers are now demanding wireless service with faster speeds, lower latency (i.e., faster connectivity), and greater capacity (i.e., the ability to accommodate more users) than current 4G LTE wireless service can deliver. … By making the false claim that it is offering a 5G wireless network where it offers only a 4G LTE Advanced network, AT&T is attempting to secure an unfair advantage in the saturated wireless market.

Here’s what the icon looks like on an iPhone.

AT&T, meanwhile, seemingly has no intention of backing down. In a statement on the lawsuit provided to Engadget, an AT&T spokesperson said:

We understand why our competitors don’t like what we are doing, but our customers love it. We introduced 5G Evolution more than two years ago, clearly defining it as an evolutionary step to standards-based 5G. 5G Evolution and the 5GE indicator simply let customers know when their device is in an area where speeds up to twice as fast as standard LTE are available. That’s what 5G Evolution is, and we are delighted to deliver it to our customers.

We will fight this lawsuit while continuing to deploy 5G Evolution in addition to standards-based mobile 5G. Customers want and deserve to know when they are getting better speeds.

Now there’s no getting around the fact that 5G E is impressively fast, but to be clear, that’s not what Sprint’s lawsuit is about. AT&T’s response to the suit seems downright bizarre and off-topic, especially given that average consumers likely don’t know the difference between 5G and 5G E, AT&T’s marketing efforts notwithstanding.

What’s more, AT&T CEO Randall Stephenson appeared on CNBC today and said that the company is “comfortable” with what it’s doing and that they are “being very clear with our customers that this is an evolutionary step.”