Patreon CEO and co-founder, Jack Conte (emphasis his):

Yesterday I learned that there was unauthorized access to a Patreon database containing user information. Our engineering team has since blocked this access and taken immediate measures to prevent future breaches. I am so sorry to our creators and their patrons for this breach of trust. The Patreon team and I are working especially hard right now to ensure the safety of the community.

There was unauthorized access to registered names, email addresses, posts, and some shipping addresses. Additionally, some billing addresses that were added prior to 2014 were also accessed. We do not store full credit card numbers on our servers and no credit card numbers were compromised. Although accessed, all passwords, social security numbers and tax form information remain safely encrypted with a 2048-bit RSA key. No specific action is required of our users, but as a precaution I recommend that all users update their passwords on Patreon.

I was sent a similar statement via email yesterday.