Brian Acton, co-founder of WhatsApp, left Facebook in 2017 over differences with Facebook founder Mark Zuckerberg on monetisation of WhatsApp. Three years before that, Zuckerberg acquired WhatsApp for a whopping $16 billion in one of the largest tech M&As then.

In 2018, Acton started messaging platform Signal, under a not-for-profit foundation by the same name. While Signal is being considered the gold standard of privacy for private conversations, it has seen an unprecedented spike in downloads from Android and Apple users across the world, leading the free app charts in nearly 60 countries. India, by sheer volume of users, has emerged as its largest market in the world, much like his previous messaging platform WhatsApp.

This time, it's the policy changes at his previous startup -WhatsApp -by the new owners-Facebook- that has led to the massive demand surge for Signal. It even led to Acton and his less than 50 members team to pull all-nighters to manage the traffic of increasing numbers of new users from across the world.

Acton spoke to Digbijay Mishra and Reeba Zachariah about the impact of the past few extraordinary days on importance of user privacy--now and in the near future, impact of WhatsApp's policy changes, Signal's India plans, and, if given a chance, would he reconsider selling WhatsApp to Facebook.

Edited Excerpts:

Q: There has been a rush to join Signal after WhatsApp updated its data sharing policy. But now that WhatsApp has clarified that the update does not affect individual chats, do you see any impact on migration?

A: There's going to be continued confusion around the privacy policy. It was complicated to read in the first place. I don't know how the clarifications will percolate into discussions on the topic. People have been talking and asking questions like should I switch to Signal? These discussions will continue because the policy is still not clear. We, meanwhile, are just excited to explain to the world that Signal has very simple terms of service and privacy policy. We're here to protect your privacy, so you don't have to worry. We have very little data, and whatever data we have is strongly encrypted, even we can't read it. We encrypt all messages, the recipients, the groups and profile photos.

Q: How many users installed Signal globally since January 6, when WhatsApp updated its terms?

A: We have seen unprecedented growth, in millions. We don't talk about our user numbers publicly. On iPhone, we shot up to the number one position in 40 countries, and on Android, in 18 countries. This is an opportunity for us to present to the world simpler alternatives. In India, we are number one. India has more people and therefore, it translates into more Signal users than anywhere else.

Q: How are you managing the surge?

A: When you have a surge of users, you have to make sure there is no outage. So, we stay up late nights to make sure we have enough capacity. Also, we have to build new relationships and listen to the users. For instance, people wanted a quoted reply feature, so we were like okay, we'll go build that. We get a supremely large amount of input, feedback, bug reports, etc. We take it all and make the product better. We will continue to release new features, not on a daily basis, but several weekly rollouts have been planned. Just today, we raised our group video chat limit to eight because we got to our next milestone of provisioning of capacity.

Q: You built WhatsApp, which Facebook later acquired. Given Facebook's controversial use of user data, how do you see the concept of privacy emerging?

A: In the near future, there will be more conversations. It's not only the nerds who are talking about data, moms and dads and kids and we are all becoming aware and educated about digital privacy, safety and security. It's good because we, as a society, are evolving together.

Q: When Facebook acquired WhatsApp, did you see a privacy situation like this one arising? Reports say that you left Facebook over differences on monetizing WhatsApp.

A: I saw it most acutely in my last year there and it was, I think part of my motivation to quit. With acquisition, they generally leave you alone in the first year. In the second year, they might have a mild oversight, but in the third year, the oversight is substantial. They had set certain goals and financial targets. For me, the decision was straightforward: To focus on the things I wanted to focus on. And, I was very excited to set up Signal foundation with Moxie (co-founder Moxie Marlinspike). After three hard years, we have a wonderful outcome, an opportunity to show what we've accomplished, and what we will continue to accomplish.

Q: Given a choice, would you reconsider selling WhatsApp to Facebook?

A: It's impossible to go back. WhatsApp fundamentally was founded as a for-profit company. There were investors and employees, who had financial concerns, including me. I will never have the chance to go back and do it differently.

Q: How big is your team at Signal? Are you planning to expand the team? How are you going to fund it?

A: We are a small organization of less than 50 people. We're always looking to hire talented engineers. We leveraged technology to provide a great service and a great product. We are a non-profit but we do have to pay employees and keep servers running. Our business plan revolves around donations and grants. So if we build a product that delights people, they are more likely to say, 'Hey, I want to support Signal'. We want to earn donations to create a sustainable organization.

Q: Since the privacy debate kicked off, has there been any noticeable spike in donations?

A: Absolutely. The month's not even over, and donations for January have already exceeded those in December. We've been focusing on growth more than revenue. As we create a larger donor base, we will have a larger revenue base to work from.

Q: Have you personally stopped using WhatsApp?

A: I use both. It's important to be aware of other messaging products for competitive reasons.

Q: Several companies are considering moving their official communication to your channel. But many others are unsure of which product to choose for commercial use. What do you suggest?

A: They should look at their needs and weigh them against the products on offer. For a long time, Facebook didn't want to use Google mail for internal communication because they didn't want Google reading their emails. In such situations, every company has to make an IT decision about how internal communications should work. Signal is a great offering because of its encryption capabilities. But it doesn't have the capacity or tools to handle a thousand-person organization.

Q: There are talks about breaking up Facebook. Do you think WhatsApp and Facebook should be made separate entities?

A: That's a tricky one. Facebook certainly doesn't want that to happen. The mechanics of doing so would be painful. It's a possibility, I suppose. It has happened historically in America, like AT&T in the 1980s.

Q: You have worked closely with Facebook and Mark Zuckerberg. What do you think of Facebook Inc?

A: Honestly, I ignore them. I made the decision to not use Facebook anymore. I wasn't a big user to start with and I've never really been much of an Instagram user as well. Maybe, I'm too old or something. I'm an outlier in this regard. Some people swear by the two platforms but for me, it's about giving people the power of choice. I'm here to present a channel of communication that's private and safe and secure. If you want to use something else, go ahead. That's your choice.

Q: With increased digital penetration, what would be the user privacy policy for Signal in the future?

A: It would be no different. We do not have any goal or ambition to collect any additional information. We either choose not to store data or we encrypt it with a lock to which we don't have a key. At all times, we seek to preserve privacy, even when we expand or add more product offerings.