The FBI is currently building a massive facial recognition database, and now we have an idea of just how big that database is. According to documents obtained by the Electronic Frontier Foundation, the FBI's Next Generation Identification (NGI) database will contain a whopping 52 million photos by 2015, up significantly from the 16 million the database contained in the middle of 2013. Beyond the size of the database, the documents obtained by EFF's Freedom of Information Act requests also showed that database includes 4.3 million images obtained for "non-criminal purposes."

It's not clear exactly where these non-criminal photos came from, but currently jobs that require a background check or fingerprinting send those prints to the FBI for its civil database. The EFF notes that similar jobs that require also an identification photo may send those images to the FBI for its database to be included alongside fingerprints.

Also of note is how this new data will be stored — the NGI database will contain both criminal and non-criminal records side by side. That's different from the FBI's fingerprint database, which kept those records completely separate — any query to the criminal fingerprint data base wouldn't ever touch the civilian data. However, searches run on the NGI will query the entire database. The EFF says that even those who haven't been arrested for a crime could have their facial images searched by the FBI.

4.3 million people who haven't been arrested for a crime have their images in this new database

It remains to be seen how these revelations will be received by privacy supporters like Al Franken, but the Obama administration recently kicked off a series of meetings to study and review the privacy concerns surrounding facial recognition technology. "Facial recognition technology has the potential to improve services for consumers, support innovation by businesses, and affect identification and authentication online and offline," the National Telecommunications and Information Administration said in a statement this past February. "However, the technology poses distinct consumer privacy challenges."

Whether or not the FBI's database will fall under its purview remains to be seen, however. While both Google Glass and Facebook have come under fire recently for the potential of misusing facial recognition technology, how the government will be kept in check has yet to be revealed.