Anyone who knows how online business works can tell you that adult entertainment drives much of the technical innovation, but it appears to be throwing up problems too after mobile porn users have started getting a little greedy.

The issue is rearing its ugly head in Japan, where unlimited phone data plans have seen networks struggle to deal with the sheer volume of horny, porny traffic.

Mobile the way to go

Aware of the groaning data pipes, Bloomberg took the time to speak to some users, including a 32-year-old travel agent who spoke lovingly of his phone: "A mobile is far handier than a computer for Internet access - I seldom use a PC outside the office."

As a result, the mobile operators have had to cap some late-night movie downloaders, even though they are supposed to be on flat-rate data plans.

Millions monthly

On the other side of the fence, the adult-movie makers are raking in money from new fans on mobile phones.

One company told Bloomberg its mobile site is pulling down around ¥15 million (£100,000) a month, mainly through membership fees.

Growth forecast

Soft On Demand's mobile chief explained: "We see the mobile phone as potentially a huge market. Fixed-rate data plans, faster internet access and sophisticated handsets are contributing to that growth."

Clearly, unless the networks work out how to handle the traffic, someone's going to end up frustrated. 4G, anyone?