"No filter is 100% accurate, " said Stephen Balkam, chief executive of the Internet Content Rating Association.

BBC: Net filters fail the children

Sina (SINA) shares are trading sharply lower this morning after Goldman Sachs analyst Catherine Leung chopped her rating on the China-based Internet company to Sell from Neutral.

FORBES: Sina Tumbles; Goldman Downgrades Rating To Sell

Yet, compelling though the Bezos vision may be, there are signs of restlessness in the ranks of generally admiring Wall Street Internet analysts, five of whom downgraded their rating of the firm's shares after Amazon's third-quarter results a couple of weeks ago.

ECONOMIST: Electronic commerce

The researchers administered several rating scales to both groups showing that the Internet over-users were also more psychiatrically symptomatic, with elevated levels of anxiety or phobias, and with significantly more problematic family backgrounds.

FORBES: Here's How Brian Williams and Rock Center Got the Science Of So-Called 'Internet Addiction' Really, Really Wrong

One example is the business need to find out what is being said about your products across the internet via product reviews and comments in places like Amazon or other rating locations.

FORBES: Collaborate to Innovate

"Not only does Tencent have a cash cow in its strong gaming business, but the company is also best-positioned in high-potential markets like social media and mobile Internet services, " said Jefferies analyst Cynthia Meng, who has a buy rating on Tencent's stock.

WSJ: China's Tencent Outperforms Its Western Peers

Shares of Internet radio player Pandora are trading lower Monday morning after Morgan Stanley analyst Scott Devitt cut his rating on the company to Equal Weight from Overweight.

FORBES: Pandora Takes A Hit As Morgan Stanley Cuts Rating