## 1 Introduction  
The social networking site Twitter first appeared on the Internet in March 2006 to provide users with a platform that they could use to communicate and connect with people around the world in as little as 140 characters. This is not limited to just friends and family, but also people you want to share with and connect to. Twitter encourages users to express themselves freely through the use of tweeting and hash tagging to \"share what you see, feel and experience as it happens\" [1]. This approach has enabled Twitter to become a central hub of real time news with breaking stories often before the media have picked them up, as well as finding out what your friends are doing. The London Riots were an example of this [2]. Twitter was used by the Police as a tool to track the rioters to try to prevent riot hotspots and other crimes that were occurring and also to keep the public informed [3]. Social media, whether it be for leisure or business has become a part of our everyday lives with Twitter and Facebook leading the way, with 645,750,000 active registered Twitter users on 11 th July 2014 [4]. People tweet on their way to work and when they get home without realizing that they are also giving away information about where they are, where they live and when they are not at home to anyone with access to the Internet. Twitter added the geo-location function to user profiles in 2009 [5] enabling followers to know exactly where an individual was tweeting from. It was only a matter of time before privacy issues regarding this information started to emerge. With geo-location now an integral part of Twitter, it is still unclear as to whether users know how to use this feature or how to protect themselves. There has been very little research to establish how many Twitter users do not realize that features such as their location and their identity are turned on by default. As most teenagers today have at least one profile on a number of social networking sites, such as Facebook or Twitter, they inadvertently reveal a lot of personal information about themselves that anyone can see and use. They do not appreciate the risks and so would not be aware that they are also exposing their private information [6]. From anecdotal observation it would appear that many users have the same picture (avatar) of themselves and the same username or \"handle\" on all of their social media sites. This makes it even easier to identify them and follow them through cyber space to harvest more personal information about them [7]. It could be said that anyone using Twitter would not necessarily realize that they could be tracked to their home simply because they uploaded a tweet or a picture to a social networking site. Furthermore, users are actively encouraged to enter a lot of personal information into social networking sites, so that this information can be shared with others [8]. This includes date and place of birth, what school they went to, name address and gender, which is all useful information for attackers. The dangers of this are identified in [9] whereby attackers could gain access to someone's Twitter account to spread malicious code or they could steal enough personal information about a user to assume their identity. This could even include gaining access to their credit card, bank details and passwords. The user may also unintentionally reveal sensitive personal information within the contents of their tweets [9,10]. Figure 1 demonstrates this, as it shows a picture of someone's credit card posted on Twitter. Anyone viewing the original post can see all the card details including the 16 digit number across the front, the person's name, the expiry date and in the case of this picture the three digit code on the back of the card is given away in the tweet. This is one of 151 million results returned from a search on Twitter for credit card pictures.