An online service that lets web users upload images to Twitter has been forced to clarify how changes to its terms and conditions affect copyright ownership of photos.

The changes to the Terms of Service (ToS) on Twitpic caused uproar on the web yesterday, after many users believed the changes meant users of ther service would be forefitting their copyright to the images when uploading them. Furthermore, some were concerned Twitpic would then sell on some images.

This lead to Twitpic founder Noah Everett posting a blog to clarify the situation.

"We recently made changes to our terms of service that has caused some confusion for our users. First off I want to apologize for that confusion and our lack of clarity. We've updated our terms again to be more clear and to also show that you still own your content," he said.

However, in the blog Everett revealed that under the new ToS, content to Twitpic, users are allowing the site to "distribute that content on twitpic.com and our affiliated partners".

"This is standard among most user-generated content sites (including Twitter). If you delete a photo or video from Twitpic, that content is no longer viewable," he added.

Everett admitted content from the site has been taken without consent of those that posted it.

"We've partnered with organisations to help us combat this and to distribute newsworthy content in the appropriate manner. This has been done to protect your content from organisations who have in the past taken content without permission," he said.

"To sum everything up, you the user retain all copyrights to your photos/videos and we are very sorry by the confusion our old updated terms of service caused."