Greece is the 6th country in the world and the 1st in Europe, regarding to the seismicity. In the past, catastrophic earthquakes have affected big cities as well as smaller areas. The mapping of a region's seismicity over time is useful for various reasons. Such reasons are scientific ones as conclusions about the repeatability of seismic phenomena, measurability of earthquakes, etc., social reasons as comparative elements of an affected area beside economic measures of a region in order for the area to recover, psychological ones as the feeling of safety for citizens, tourists etc.. The Geodynamic Institute of the National Observatory of Athens holds the national role of recording seismic stimuli to subsequently scientifically extract the characteristics of the earthquakes. Apart from the Geodynamic Institute, there are international networks for the recording of strong seismic vibrations (e.g. USGS, CSEM-EMSC, GDACS etc), but the recording of seismic events by seismographs near the affected area is considered to be the most reliable data source. New technologies are increasingly penetrating all scientific fields and software tools are available to the scientific community as well as to the general public that capture the recorded seismic activity of the regions and publish the results. Such a tool for mapping geo-referenced seismicity is the Google Earth application. The published data by this application are not on-time. The available data in Google Earth as well as in GI-NOA, are: Date, Time (UTC), Latitude Longitude, Depth, and Magnitude. Deviations of the data available from the Earthquake Directories of the GI-NOA website in relation to the Google Earth site were observed. Specifically for major earthquakes (such as Thessaloniki 1978, Alkyonides 1981, Parnitha 1999, Andravida 2008, Kefalonia 2014, Kithira 2006), a difference in the size of 0.6R was detected, while the acceptable difference between seismic measurements is 0.2R in Richter’s Magnitude Scale. Significant differences were also found in the recorded depths of the earthquake of 30 km. The earthquakes up to 1982 have no depth reference to GI-NOA (except in very deep cases), while there are corresponding reports in Google Earth. No significant differences were found about the Latitude and Longitude of the two WebPages. The period of the study was at the middle of January 2018. In conclusion, there is highlighted the precision of data available through geo-referenced data sources, that are hosted and published worldwide through modern technological tools, such as the well-known Google Earth application. The Data Banks from which the scientific data are derived should be the National Databases of the affected area. The National State must establish and carry out a control on each website or application, which distributes geo-referencing of seismic events’ data.