Instagram, Pinterest, Aviary: The Social Photo Feud Heats Up More drama for photo sites, social gifting, the pope on Twitter and other social-media news from around the web.

This week's need-to-know social-media news.

Some of the hottest social companies have been acting lately like fickle teenagers. Last Sunday, Instagram broke up for good with Twitter, making it impossible to embed Instagram photos in tweets. A couple of days later, Twitter users started noticing that photos posted to Pinterest's pinboards were displaying within their Twitter stream.

It didn't end there. Twitter later announced a suite of its own photo-filtering tools, powered by New York City-based startup Aviary. It remains to be seen whether the new service will replace Instagram among camera-happy mobile users, but Twitter's new image filters are certainly worth a test drive. -- Wired and SocialTimes

Amazon and Facebook partner for social gifting.
Online retailing giant Amazon has partnered with Facebook to launch a "Friends and Family Gifting" feature, which allows you to track your Facebook connections' birthdays and anniversaries on Amazon, and view their Amazon wish lists. Not only can this help with your holiday shopping, it might help influence the greater gifting market, including startups such as San Francisco-based Wantist and Wantful. -- Mashable

Facebook users reject privacy changes.
In a move potentially surprising no one, Facebook says it will not be bound by its users' vote against the proposed privacy changes it plans to make. The social network sent an email to users, inviting them to vote on the changes. And while a resounding 88 percent of the 750,000 or so respondents voted against the changes, the vote was all for naught. Facebook said the vote would be non-binding unless at least a third of its active users -- some 300 million people around the world -- participated. -- SFGate

Ads may be coming to Instagram.
Instagram users who are enamored with the photo-sharing site's clean interface may be in store for some less-than-appealing changes. A Facebook executive this week confirmed that it is developing a strategy to make money from the popular photo-sharing tool it acquired earlier this year. While the executive declined to offer specific details, a good bet might be that ads will be involved. If so, could ads lead to a fall in user traffic? -- BetaBeat

'And now the pope will tweet!'
Yes, Pope Benedict XVI is now officially a tweeter. The leader of the Catholic Church joined Twitter (@Pontifex) and sent his first tweet this week. In just a matter of days, His Holiness has already racked up more than a million followers, despite sending only seven tweets (so far). His latest tweet received nearly 20,000 retweets. -- Business Insider