SINGAPORE - Messaging app Telegram has been in the news recently for all the wrong reasons - such as for being linked to crime, misinformation and abuse.

The app has also made waves overseas, with Germany considering a ban on it due to an influx of extremist content, including anti-vaccine conspiracy theories that have led to threats of violence.

But what is it that has made the app so popular - it now has more than 500 million users - and a hotbed for scams? What can be done about its problems? The Straits Times explains.

1. Mega chat group size a draw

Mr Bryan Tan, a lawyer from Pinsent Masons MPillay who specialises in technology law, attributes Telegram's popularity to its large chat size that can go up to 200,000 users - compared with WhatsApp's 256-user limit.

"This allows Telegram to be used for mega-sized groups, almost like a news site, without having to run expensive content servers," he said, adding that the app also allows users to send large files.

2. Phone number not needed for account registration

It is optional to provide a phone number when registering a Telegram account.

"Anonymity plays a large role in the spread of misinformation, because there is no mechanism of accountability," said Associate Professor Edson C. Tandoc Jr from Nanyang Technological University (NTU).

Prof Tandoc, who is from NTU's Centre for Information Integrity and the Internet, added: "Take, for example, anti-vaccination groups, where people share information that may not be backed by evidence. Just the volume of messages that come in every day can make it convincing for some people."

But a larger issue arising from the growing use of Telegram and the anonymity it affords is the formation of extremist groups, said experts.

Ms Tania Chin, a partner in the criminal litigation team at law firm Withers KhattarWong, said: "Coordination of terror attacks, espousing terrorist ideals and the spread of disinformation are still the greatest threats."

3. Lack of default end-to-end encryption

Dr Natalie Pang, senior lecturer and deputy head of the Communications and New Media Department at the National University of Singapore, said end-to-end encryption is not provided by default on Telegram as it is with other apps such as WhatsApp.

The encryption ensures that only the two users communicating can access the information shared on the chat.

"In other words, chats in Telegram can still run the risk of being leaked and accessed by third parties," Dr Pang said.

This means hackers can use Telegram to spread malware or ransomware to steal or lock up users' data.

4. No default limit on message forwarding

While Telegram group chat owners can restrict forwarding from their chat, if that option is not chosen, there is no limit to the number of times a message can be forwarded on the app.

WhatsApp, which has two billion users worldwide, imposed limits in April 2020 after it attracted negative press over the spread of fake news related to the Covid-19 pandemic on its platform. Under the new rules, a user will be able to send a message to only one chat at a time if the message has already been forwarded more than five times.

5. App ban will not solve wider problems

Mr Benjamin Ang, who serves on the executive committee of the Internet Society Singapore Chapter, said banning the app will force users to find other ways to share information.

"Apps and platforms come and go, so instead of trying to play catch-up by regulating every new platform that appears, another way is to pursue the people who spread extremist content or dangerous disinformation," he said.

Dr Jiow Hee Jhee, a member of the Media Literacy Council, said risks posed by Telegram are not significantly different from other apps.

Ms Chin said: "Ultimately, public education on safe digital practices would be a longer-term solution."