For many iPhone users, there is a common annoyance when it comes to texting: a friend switches to Android and the message bubbles in the group chat turn green.

When people text between iPhones and Android phones, things start to break down: pictures and videos get pixelated, messages sometimes don’t send, or they’re late or out of order. Typing indicators will be disabled, and reactions, like a thumbs-up or a heart, will be spelled out as text instead of showing up as badges on the bubbles. People have been complaining about this for years.

Google launched a marketing campaign on Tuesday criticizing Apple over the problem. The search giant released a website called “Get the Message,” urging people to call Apple on social media for “broken group chats.”

“It’s time for Apple to fix SMS,” the website reads. “These problems exist because Apple refuses to adopt modern SMS standards when people text each other with iPhones and Android phones.”

The site also points to alternatives to Apple’s iMessage that are good for sending text messages between operating systems, including privacy-focused chat app Signal and Meta’s own WhatsApp.

The campaign is Google’s most aggressive move yet to convince Apple to make its SMS service compatible with Android phones, breaking the decency in which tech giants rarely call each other names. Teens and college students reportedly fear being ostracized for green blisters The Wall Street Journal. Earlier this year, Android’s top boss Hiroshi Lockheimer said Apple’s upper hand in texting was the result of “peer pressure and bullying.”

Apple did not immediately respond to a request for comment.

The reason for the problems is the technology behind the messaging services. Apple uses SMS, or Short Message Service, and MMS, or Multimedia Message Service – two robust but outdated protocols released in the 90’s and early 00’s. Google is pushing Apple to adopt RCS, or Rich Communication Services, a newer protocol the company rolled out in 2019 to modernize how texting is sent on Android phones. Bringing both iPhones and Android phones to RCS would also mean messages could be end-to-end encrypted between the two operating systems, which is a glaring security issue at the moment.

Despite its reputation and brand awareness, Google has long struggled to create successful messaging apps for its platforms. The company has released and shut down several SMS services over the years, including Hangouts and Allo, which haven’t gained traction with consumers.

For Apple, the green bubble strategy is intended. “In the absence of a strategy to become the primary messaging service for [the] Most of the mobile phone users I fear that iMessage on Android would simply serve to remove them [an] Barrier for iPhone families to give their kids Android phones,” Craig Federighi, Apple’s senior vice president of software engineering, said in a 2013 email. The email was released last year as part of an antitrust lawsuit between Apple and Epic, makers of the popular Fortnite video game.

In another email, a former Apple exec put it bluntly: “iMessage amounts to serious engagement.”