Today's Tech: O2 announces entry to 4G party, Twitter roundly criticised after bomb threats and New York Moto X launch event

EE's reign as the sole UK provider of 4G mobile services is nearly over, as O2 this morning announced a 29 August launch for its own high-speed mobile network. London, Leeds, and Bradford will be the first locations covered by the O2 spectrum at the end of the month, reaching some five million people. By the end of 2013, the Telefónica subsidiary plans to offer 4G in a total of 13 cities, with further switch-on dates set to be revealed in the "coming weeks." O2's 4G contracts will start from £26 a month - £5 more than EE's cheapest 4G rate. The company says its 4G networks will provide data speeds up to five times faster than its current 3G services. As with customers who upgraded to EE's network, existing O2 customers will require a 4G-enabled phone and 4G data plan to take advantage of the new spectrum.

Despite the rapid rise of Google Chrome, Internet Explorer is still very much the world's leading browser, with almost 57 per cent of the market. Although the latest numbers from web research firm Net Applications show Chrome was the biggest winner in terms of market share gain in July, the expected demise of Internet Explorer in some quarters is still some way off, with Firefox more likely under threat. Between June and July, Internet Explorer gained 0.46 percentage points to take its share to 56.61 per cent. Meanwhile, Firefox lost 0.86 per cent to go down to 18.29 per cent. Chrome on the other hand went up by 0.59 per cent to reach 17.76 per cent, and Apple's Safari slipped 0.13 per cent to 5.42 per cent, and Opera went down further to a paltry 1.49 per cent. The last time Firefox had such a low share of the browser market was over five years ago, before Chrome even appeared, so its future doesn't look that bright, going by Net Applications' figures. Chrome is set to surpass Firefox some time this year if present user trends continue.

Several female journalists have received bomb threats on Twitter, prompting the police to launch an investigation. The Guardian's Hadley Freeman, the Independent's Grace Dent and Time magazine's Catherine Mayer were the three people targeted. Anonymous Twitter users tweeted that bombs had been placed outside the victims' houses were scheduled to detonate at 22.47 BST. Dent, who called the threats "a new low," took a screenshot of one of the messages, which read, "A BOMB HAS BEEN PLACED OUTSIDE YOUR HOME. IT WILL GO OFF AT EXACTLY 10.47PM ON A TIMER AND TRIGGER DESTROYING EVERYTHING." The Metropolitan Police has since launched a formal investigation into the threats. Freeman admitted she did not leave her home because she "did not think it was worth taking that seriously," but called for Twitter to improve the moderation of its site. A petition calling for Twitter to implement a 'Report Abuse' button on its website was recently established by social media users in response to rape threats sent to feminist Caroline Criado-Perez. It has, so far, attracted over 110,000 signatures.

Apple CEO Tim Cook reportedly met with China Mobile chairman Xi Guohua in Beijing this week to discuss a partnership with the only major Chinese carrier that doesn't offer the iPhone. China Mobile has an estimated 740 million subscribers, making it the largest carrier in the world, and is in possession of just under 65 per cent of China's mobile service customers. While China's two other state-run telecoms, China Telecom and China Unicom, both sell Apple's iPhones, China Mobile's TD-SCDMA 3G network is incompatible with pre-iPhone 5 smartphones from Apple. However, the carrier's buildout of a TD-LTE-based network for 4G service means Apple's current generation of devices could be offered. Though Apple now has a foothold in China thanks to its deals with China Telecom and China Unicom, the bulk of the country's estimated 988 million mobile users will remain tantalisingly off limits for Cupertino until an agreement with China Mobile is reached. Earlier this year, reports suggested that Apple is seriously lagging behind rival Samsung in China, with smartphone market share in the single digits compared with Samsung's nearly 25 per cent share of the China market.

Finally, the new Moto X is set to be unveiled at a big launch event in New York tonight. We have pictures, specs, leaks and rumours - in short, everything you might want to know about Motorola's upcoming flagship device. Google is very excited about it, and we know that most of the world is still mystified as to what the customisable features will be.