As the title of this post suggests, that is what Minerazzi (http://www.minerazzi.com) does. Our original project has evolved into a decentralized platform for building topic-specific collections that researchers, students, and the general public can use to data mine while searching. You can search in English or Spanish.
A sample of public miners built with the platform is given below. Feel free to submit relevant, qualified resource URLs.
Ebola - The Ebola Virus Collection
Chikun - The Chikungunya Virus Collection
Grants - Search for grants and scholarships
PRBusca - Search Puerto Rico government agencies
and many more.