One of my freelance client has been asking his customers to put backlinks on footer to link back to his client site. e.g. "Powered by BHW". So whenever his customer's site publish a page/post, it will appear as a backlink to his site. There are answers i need to know: 1) Do you think i shall disavow its "EXTRA backlinks" from one domain, but retaining only homepage backlink? 2) Does 30k backlinks from 30 RD resulting in penalize? 3)What is the next step?