Utility companies have been seeking methods to operate electricity distribution infrastructures efficiently. Smart grid applications provide opportunities to network operators to collect data from consumers. Therefore operators could track power consumption based on historical and immediate data. Thanks to remotely collecting data, operators take necessary action to manage changes in consumption rate and types. Although smart grid application make grid operators manage their network reliably and effectively, these new applications pose new vulnerabilities and security threats because of insecure designs and products. Most of the vulnerabilities result from commercial off shelf products, operating systems, access technology and communication protocols. In this paper, security considerations on smart grid application, particularly data network securities are discussed. In addition, some applicable measures to mitigate currently available vulnerabilities are proposed.