In an effort to increase transparency in its handling of controversial and legally tenuous messages sent via Twitter, the online social-networking service has changed its policy in cases of alleged copyright violations: Now, it will not be "removing" tweets but "withholding" them.

The change, reported by the tech site GigaOM, was announced on Twitter itself by a member of the service’s legal team.  Jeremy K. tweeted that the "Copyright and DMCA Policy" was changed in the name of “#transparency.” DMCA is the acronym for the Digital Millennium Copyright Act.

Twitter explained on its revised copyright-policy page, "In an effort to be as transparent as possible regarding the removal or restriction of access to user-posted content, we clearly mark withheld tweets and media to indicate to viewers when content has been withheld." It also gave a couple of examples of the way this marking will look.

Previously, a user considered to be in violation of a given copyright simply had the message deleted outright by Twitter with little or no recourse available to retrieve his or her own material.

Under the new policy, if a copyright holder requests the takedown of a tweet and Twitter complies, then the offending tweet will read: “This tweet from @Username has been withheld in response to a report from the copyright holder,” with a link to the changed policy.

Meanwhile, media withheld by Twitter under similar circumstances will be replaced by a slide reading, “Media not displayed: This image has been removed in response to report from the copyright holder."

While Twitter will still technically be removing the allegedly infringing material, its new policy gives users more contextual information about the offending content. Displaying the message on the user’s Twitter feed also allows his or her followers to respond to the message, rather than leaving other users with a dead link.

To comply with the DMCA, Twitter is obligated to remove any user-generated content that violates a copyright agreement. If a company such as the privately held Twitter or Google Inc. (Nasdaq: GOOG) neglects to police its users’ behavior in this way, it risks facing legal charges by copyright holders.

Critics of the DMCA -- and Twitter’s approach in complying with it -- have argued that this allows users with any sort of vested interest to force the company’s hand in removing content with the threat of legal action alone.

Because any allegedly offending content will be blocked to the average Twitter user under the new policy, the company is essentially washing its hands of any such offending content. However, it is doing so in a manner that distances it from any of the restrictions themselves.

In contrast, Google has been more aggressive than Twitter in opposing the DMCA’s provisions, arguing that many copyright holders make claims to hamper their competitors, rather than to actually protect the contested material. This behavior risks leading to conditions that could result in controversial but legal content being kept under wraps because of the threat of judicial coercion, which open-Internet advocates are battling via such means as Chilling Effects.   

Twitter noted in its new policy that the company will provide the Chilling Effects database with a copy of each message removed due to a DMCA-related complaint.