Unfortunately, despite the enthusiasm for new forms of Big Data, there has been relatively limited critical research into their validity for geospatial research on real-world phenomena. This is foremost because the provenance of big datasets is often unknown and it may be difficult to link records to alternative databases. In addition, the unstructured and unregulated nature of some datasets has deterred some from using them at all. Whilst Big Data are useful for countless applications, it is important to be cognizant of their limitations. This section describes the core fundamental challenges to harnessing Big Data to form geospatial representations. It is important to consider that these challenges may not apply to each data source to the same extent. Each big dataset will have its own merits and deficiencies that researchers should seek to explore.