Bitcoin is surging in China, but the explosion in digital currency trading has been accompanied by possible fraud and theft.

GBL, a Chinese bitcoin trading platform that claimed to be based in Hong Kong, recently shut down – an event that might not be worthy of note had ¥25m ($4.1m) worth of users’ money not disappeared with it.

The company appears to have launched in May 2013, with its domain btc-glb.com registered on 9th May and a post later that month by Bitcoin Talk forum user zhaoxianpeng promoting the site.

Commenters were instantly suspicious, noting that the site’s server was based in Beijing despite the site's claim to being based in Hong Kong.

They also pointed out that GBL hadn’t provided straightforward contact information on their site and that the platform used a patchwork of information lifted from other websites.

Those weren’t the only warning signs. According to WantChinaTimes.com, which quotes a report from Chinese newspaper Southern Weekly, GBL registered as a company with the Hong Kong authorities on 10th June but never received a license for financial services.

Despite these concerns, it seems GBL was able to attract 1,000 mainland investors, according to a report from Hong Kong-based newspaper The Standard.

The forum thread now has a large red warning notice from a moderator at the top that reads: “Be careful scam.”

By September, GBL began issuing stock to its users, and in early October it was capping the amount of money users could cash out. Those actions could have been to maximize the amount of money it held.

Soon after, on 26th October, GBL shut down and vanished without a trace.

The address listed on its website proved to be a fake – “the office listed on its website […] turned out to be a false address,” reports The Standard – and the Hong Kong police have now been involved.

Bitcoin’s history is littered with these kinds of stories, which appear to show behaviour that is not entirely above board.

This list

gives some sense of the number of times bitcoiners have been persuaded to part with their money, only to find that, whether by malice or by incompetence, they couldn’t get it back.

The theft of over a million dollars worth of bitcoin from Australian wallet service Inputs.io is probably the most recent infamous case.

Inputs.io may have been a case of incompetence, with some questioning whether the service did enough to secure its users bitcoins.

With GBL, the evidence points towards malice but the warning signs were there. For 1,000 investors, though, the excitement of getting on the bitcoin gravy train seems to have suppressed their better judgement.

Just over a week ago, BTC China, the first trading platform to trade bitcoins for Chinese yuan, shot past Mt. Gox to momentarily become the world’s number one bitcoin exchange and, on the ground, businesses are beginning to awaken to the digital currency’s potential, with a bar in Beijing leading the field by becoming the first in China to accept bitcoin.

In the land of the “Great Firewall”, the success of bitcoin, the currency of the Internet, is obviously attracting a great deal of attention.

Like elsewhere, it seems it is also attracting sharks ready to take your money if you’re not careful. Watch out.