Twitter’s advertising rates fell again in the last three months of 2013, according to the company’s annual report released Thursday. The cost of advertising on Twitter dropped 18, the seventh straight quarter of declines. The trend is worrisome for Twitter, but for now it isn’t a big deal that advertisers are paying less for each ad unit. Advertisers are overall spending more on Twitter because more users are clicking on ads. The engagement growth shows advertisers that ads on Twitter work, thus spurring more demand. It more than doubled to $220 million in the last three months of 2013 compared to a year earlier. br Google’s Eric Schmidt told a SXSW audience in Austin Friday that Google is “very, very worried about” the growing financial inequality and subsequent protests in San Francisc . He predicted that inequality will become “the No. 1 issue of democracies, and said, "technology can help some, but inequality is growing.” He and President Obama have both pushed for more education in science, technology, engineering, and math to help fill unmet demand for tech jobs. br Steve Jobs was once asked at an Apple shareholder meeting by a shareholder who wanted get some insights into his deepest thinking: “What keeps you awake at night?” Mr. Jobs replied, “Shareholder meetings.” The wisdom of this insight was borne out last week when Mr. Jobs’s successor at Apple, Tim Cook, was asked at the annual shareholder meeting by the NCPPR, the conservative finance group, to disclose the costs of Apple’s energy sustainability programs, and make a commitment to doing only those things that were profitable. Cook replied "When we work on making our devices accessible by the blind, I don’t consider the bloody ROI. We want to leave the world better than we found it.” br People shouldn’t send sensitive information over public Wi-Fi hot spots because it risks being stolen, the top cybercrime police officer at Europol warned Friday. Troels Oerting, head of the cybercrime center at Europol—the agency co-ordinating the work of police forces across Europe—said consumers should send personal data only across networks they trust, given the growing number of attacks being carried out by hackers through via public Wi-Fi in places like shops, cafes and restaurants. The concerns from Europol come as cable groups like Comcast and Time Warner, supported by computer operating giants like Microsoft and Google, bid to expand the growth of Wi-Fi amid soaring global data traffic by pushing for the release of more telecom spectrum for unlicensed use.