Around 191 million US voter registration records have been leaked due to some database configuration issue. A whitehat hacker has uncovered the massive database sitting on the web just like that. Nobody has a clue exactly who is responsible for this leak.
The 300 GB of voter data includes, according to this Forbes report, names, home addresses, phone numbers, dates of birth, party affiliations and information on whether or not they had voted in primary or general elections. The data goes as far back as 2000. The only saving grace is that the data does not contain financial data or security numbers.
It is being speculated, as reported in CSO, that the database came from the political data firm NationBuilder but the company may not be directly involved with the leak. Most probably, one of its customers purchased the database and then made it public, either purposely or by mistake. CEO Jim Gilliam, in a public statement has said that the information is already publicly available and the information contained within the database can already be obtained from various government websites.
The information contained within the database can be used to stalk people or simply harass them. Dates of birth and political affiliations information can also be used to mount targeted phishing campaigns.