If you really love the icon set, you can support Hawcons by donating a little value.
You are free to use Hawcons for commercial and personal purposes without attribution, however a credit for the work would be appreciated. You may not sell or redistribute the icons themselves as icons. Do not claim creative credit. If you would like to support the work you can do this with the donate button on the website. If you have any additional questions please contact Hawcons via email or social networks.