The terror attack that killed 10 and injured 15 in the historic Sultanahmet Square shook Istanbul on Tuesday, prompting tighter security measures across the country.As Prime Minister Ahmet Davutoğlu announced that the assailant of the Istanbul attack was a 28-year-old Syrian national who had links to the Daesh terrorist organization, many have been in search of signs which would lead to clues on how the attack was planned and those behind it.Perhaps the most interesting emerged on Twitter: On Tuesday a tweet showing Wikipedia search statistics sent by Ali Ihsan Özkeş who has a PhD in Economics in France, hinted that the Istanbul attack was indeed planned, and the perpetrators had done their research online. The tweet is made up of four photos showing the search statistics for the term "Sultanahmet Hippodrome of Constantinople".Each photo shows the number of views of searches related to Sultanahmet in the languages of English, Arabic, Turkish and Russian.For those who wonder what sort of tie a hippodrome has with the Sultanahmet square, let's clarify:In Byzantine times when Istanbul was called 'Constantinopletarget="_blank"'>These photos alone are not enough to make an analysis, but these search results could be an anomaly to look out for in ongoing investigations.