The problem is that what they've written looks very reasonable. After all, who could disagree with a statement such as the quote below?
"It is in no-one’s interest for the foundations of strong societies and stable
democracies – the rule of law, privacy and security – to be undermined."
The Internet is a dangerous place at times. As anyone who needed the NHS a few days ago is all too aware, modern technologies can be vulnerable to very damaging attacks. There are whole new variations of criminal activity, from bullying and harassment to fraud and identity theft, that have been enabled by our modern, highly connected lives, and these often do have serious consequences for the victims. None of this is seriously in dispute, and no-one would seriously suggest that it wouldn't be better if these problems were effectively addressed.
The real problem is that I suspect Theresa May and her government have a very different idea about what things like "effectively addressed" mean compared to most of us here. The biggest single step to undermining privacy and security online in our country may well have been the Internet surveillance laws passed recently by the current government, laws which started out as a personal goal of May herself from her time as Home Secretary.
In their haste to ensure that laws and principles can be applied online as well as offline, it appears that the Conservative leadership has forgotten that offline we also have rules about following due process and principles about being innocent until proven guilty and legal requirements for reasonable grounds for suspicion before doing various things that interfere with a private citizen's life.