Flickr has published a blog post chiming in on the controversy surrounding intellectual property rights and the usage of photo services such as Twitpic recently.

“We feel very strongly that sharing online shouldn’t meant giving up rights to your photos,” says Flickr’s Zack Sheppard.

“Our Terms of Service clearly spell out that Flickr/Yahoo! doesn’t own the photos that you upload.”

Sheppard goes on to say that Flickr asks for just enough of a license to perform essential services such as resizing images and generating thumbnails. Flickr is quick to mention that it gives users the ability to post and discover images by license, focusing on the variety of Creative Commons licenses it supports.

The Twitpic controversy began after the company signed a deal with news agency WENN, selling media photos posted by celebrities for use in third-party content. Twitpic amended their terms at the same time as the agreement was launched, giving themselves the license to exploit photos for commercial gain.

Users are worried that, while absolute ownership always remains in the hands of the uploader, the licenses granted to these services are far too extensive.

It’s not a fear that consumers have in vain. In March we posted about the story of Noam Galai, who uploaded a picture to Flickr and forgot about it — until it started showing up on shirts, magazines and other merchandise in 40 countries around the world without any attribution or revenue going to him.