It depends more on how big their scale is and what sort of technology measure is being required of them.
For example, you order an ISP to use deep packet inspection, which is a form of inspecting the headers on packets of traffic that tells you a lot about the type of traffic being carried. If that's used as a method of trying to detect infringing traffic—and we won't talk about the merits of how accurate it is or isn't, but let's assume it is—those DPI boxes can easily cost $100,000 each. For a small ISP, you could literally put an ISP that's comprised of two to four employees out of business by requiring them to do this.