Blu's unlocked Android phones are back on Amazon after a "false alarm," the company told Engadget. The online retail titan pulled down all Blu models from its website a couple of days ago. It cited "security concerns" after security firm Kryptowire reported that the manufacturer is still collecting user data and sending it to a server in China. Blu admitted last year that the third-party software it used to push software updates collected unauthorized messages, call logs and contacts. However, it refuted the new report that its phones still collect sensitive information.