Unless the US changes how it distributes and tracks sensitive information, the short answer is “yes.”
After the terrorist attacks of 9/11, agencies began sharing information that previously had been “stove-piped.” At the same time, the number of individuals with access to classified information via the secure Secret Internet Protocol Router Network grew to nearly 2.5 million people (most of them at the Defense Department). Manning was one such person.
“Obviously that aperture went too wide,” Defense Secretary Robert Gates told Pentagon reporters recently. The Pentagon is now tightening controls on classified information. For example, classified computers will be “read-only,” preventing the use of thumb drives and other removable media to copy and walk away with sensitive data.
The State Department and other agencies, too, are tightening information-sharing. Moreover, the White House has directed government entities that handle classified information to review their "implementation of procedures for safeguarding classified information against improper disclosures.”