Several apps and sites like longform and readability offer users a "read view" of other people sites which strip the content of ads and change font etc to make the text easier to read. I am working on a similar concept and wanted to check what legal issues are involved with doing that.

Several apps and sites like longform and readability offer users a "read view" of other sites, which includes stripping the content of ads and changing font to make the text easier to read. I am working on a similar concept and wanted to check what legal issues are involved with doing that.