The Sex Offenders Registration Act 2004 provides that when a person is sentenced for registrable offences (certain sexual offences) they automatically become a registrable offender. Part 3 requires registrable offenders to report for either 8 or 15 years, or for life, depending on why they are defined as a registrable offender.
Alternatively, a court might order that certain offenders comply with reporting conditions under the Act.
Similar provisions operate in the UK. In F (A Child) v Secretary of State for the Home Department; Thompson v Secretary of State for the Home Department  UKSC 17 the UK Supreme Court considered the notification period for people convicted of prescribed sexual offences.
If a person is sentenced to 30 months or more jail, the notification period is for life.
F and Thompson argued that the notification requirements were incompatible with Article 8 of the European Convention on Human Rights, which provides:
Article 8 – Right to respect for private and family life
1. Everyone has the right to respect for his private and family life, his home and his correspondence.
2. There shall be no interference by a public authority with the exercise of this right except such as is in accordance with the law and is necessary in a democratic society in the interests of national security, public safety or the economic well-being of the country, for the prevention of disorder or crime, for the protection of health or morals, or for the protection of the rights and freedoms of others.
The question in F and Thompson was if the lifetime reporting requirements were disproportionate to the provision’s aim of preventing crime and protecting the rights and freedoms of others. F and Thompson argued the notification requirements cold not be proportionate because there was no right to review if they continued to be justified in individual cases.
The Supreme Court adopted a test for proportionality laid down by the Privy Council.
The approach to proportionality
[17.] In order to decide whether interference with a fundamental right is proportionate to the legitimate end sought to be achieved the court has to ask the questions identified by the Privy Council in de Freitas v Permanent Secretary of Ministry of Agriculture, Fisheries, Lands and Housing  1 AC 69 at p 80:
“whether: (i) the legislative objective is sufficiently important to justify limiting a fundamental right; (ii) the measures designed to meet the legislative objective are rationally connected to it; and (iii) the means used to impair the right or freedom are no more than is necessary to accomplish the objective.”
However, as Lord Bingham of Cornhill observed in Huang v Secretary of State for the Home Department  UKHL 11;  2 AC 167 at para 19, there is an overriding requirement to balance the interests of the individual against those of society.
The Court then considered other supervision and management mechanisms in the UK legislation, noting it was possible in some cases to vary notification requirements under those provisions, in contrast to the mandatory requirements involved in this appeal. The Court also accepted at  there was no point continuing with notification requirements if a person could demonstrate they were no longer a significant risk of committing further serious sex offences.
Counsel for the Home Secretary put the counter argument.
[52.] Both the Divisional Court and the Court of Appeal proceeded on the premise that there were some who were subject to notification requirements who could “clearly demonstrate” that they presented no risk of re-offending or of whom “it can confidently be said that there was no risk” that they would commit a sexual offence. Mr Eadie came close to admitting that, if this premise were correct, it would be hard to gainsay the proposition that there ought to be a right to a review to enable notification requirements to be lifted in respect of those who no longer posed a risk. He submitted, however, that the nature of sexual offences was such that it was never possible to be sure that someone who had been guilty of a serious sexual offence posed no significant risk of re-offending, and that this was borne out by statistical evidence. Either all sexual offenders had a (possibly) latent predisposition to commit further sexual offences or, if some did not, it was impossible to identify who these were. Whether these submissions are well founded is the question that lies at the heart of this appeal. I turn to consider the evidence before the court.
The Court concluded there was no evidence it wasn’t possible to identify those who might re-offend, but that 75% of supervised offenders were not convicted of further offences. Lord Phillips concluded at :
…I think that it is obvious that there must be some circumstances in which an appropriate tribunal could reliably conclude that the risk of an individual carrying out a further sexual offence can be discounted to the extent that continuance of notification requirements is unjustified…
(I think there’s a bit of an evidentiary leap there. The starting point is the liberalist idea of primacy of the autonomy of the individual, which triumphs over the absence of evidence to justify interference with that autonomy. It’s not necessarily wrong, but to raise that almost as an afterthought at the end of the argument leaves the syllogism open to challenge.)
The end result was that the notification requirements were held to be disproportionate and so incompatible with the right to privacy and against arbitrary interference, and the Court issued a statement of incompatibility. (Though we know from Momcilovic’s case, under Victoria’s Charter that doesn’t necessarily mean anything has to change.)