Why did so many people oppose the Act?

Here is a brief outline of arguments against aspects of the Act. Some of the blog posts we've collected links for give more detailed objections.

Arguments against termination of Internet access

Internet access is now an important necessity for participation in society and the economy, and cutting it off is not an appropriate punishment.
The Act does not provide due judicial process, or afford the presumption of innocence.
Your Internet connection can be cut off because of unproved allegations, without a court hearing, and if you appeal you have to pay part of the legal cost yourself.
People who have not downloaded or infringed copyright may be cut off if someone else does so from the same household, or by using their wireless connection without authorisation.
It will be hard for small businesses, libraries and so on to offer public Internet and wireless connections if they are at risk of cut-off through actions of a few customers.

The terms of the Act, concerning Internet "locations", are so vague that even search sites like Google could be subject to them.
Blocking web sites is a bad precedent which could lead to wider censorship, e.g. against sites like WikiLeaks.

The parliamentary process which passed the Act was hurried, few MPs participated in discussion, and there was a lack of understanding of technical and social issues.
The figures presented by proponents of the Act on loss to creative industries through file-sharing are unsubstantiated and exaggerated (see GAO report and blog posts on it [1] [2] [3]).
File-sharers are also among the biggest purchasers of content [4]
In any case, cutting off people's Internet access or threatening to do so will not mean they spend money buying more music or culture.
The Act threatens to stifle digital innovation, by cutting public wifi and innovators' Internet connections and websites [5].
The Act will prompt people to install encryption and other technical workarounds, making it harder to detect criminals who use such methods already.
A better approach would be to update copyright laws and help artists and creative industries develop new business models which will support cultural production without inhibiting sharing.