In a real democracy the majority would actually make the laws. A fine of $100 sounds fair, it is still a punishment and would be much more acceptable to police heavily (and with less lawyers involved). I would be fine with automated fines of $100 being handed out to people downloading a file illegally and I think that would be a more effective deterrent than the present lawsuit madness that rules copyright.
IMO one should never be okay with automated fines of any kind, especially on the Internet. There is far too much potential for false positives, and too much difficulty identifying when a particular download is illegal. Not to mention, there would be a very strong incentive for the hosts of pirated material to find ways of bypassing the fines and blocking their crawlers. Griefers will install malware on others' comput…
There is the same incentive now for blocking MediaSentry and the like, why would the change escalate this? Griefers already do this too but usually with material far more illegal than music.
The present system doesn't make sense. It should not be OK for a company to bankrupt someone over something that can be legally purchased for a minimal amount. Both enforcement and defence against enforcement are too expensive, time-consuming and economically pointless. Having an efficient system is better than having an inefficient system.