In the face of an exploding range of volunteered data initiatives, it is important to maintain good metadata and quality information in order to ensure the appropri-ate combination and re-use of the resulting datasets. At the same time, there is in-creasing evidence that validation and quality assessment of data (whether that data be volunteered or ‘official’) can sometimes be usefully crowdsourced, i.e. the required efforts can be distributed to a large number of people. However, as with VGI itself, maintaining the consistency, semantics and reliability of volunteered metadata present a number of challenges. Initiatives which archive the history of features and tags (e.g OpenStreetMap) lend themselves to some mapping of dis-puted features, but among citizen science projects in general there is often limited scope for users to comment on their own or others’ submissions in a consistent way which may be translated to any of the currently accepted geospatial metada-ta standards. At the same time, platforms which allow the publication of more ‘authoritative’ datasets, (e.g. Geonode and ArcGISOnline), have introduced the option of user comments and ratings. Volunteered metadata (on both authorita-tive and VG information) is potentially of huge value in assessing fitness-for-purpose, but some form of standardization is required in order to aggregate di-verse ‘opinions’ on the content and quality of datasets, and extract the maximum value from this potentially vital resource. We discuss major challenges, and pre-sent a set of examples of current practices, which may assist in this aggregation.