Formerly Free Britain
Bitter has a post where she mentions a variety of ways the British authorities can get access to homes without authorization. Needless to say I had to look some of these up. Now, keep in mind this is national legislation in the country that gave us the Magna Carta and John Locke (toss in Adam Smith too if you want to include Scotland).
Bitter said one way was to "survey your home and garden to see if your hedge is too high (Anti-Social Behaviour Act 2003)". Sure enough, Part 8, section 65 refers to a complainant whose "reasonable enjoyment of that [the complainant's] property is being adversely affected by the height of a high hedge situated on land owned or occupied by another person".
Part 8, Section 74 defines then goes on to define the "powers of entry" the authorities have in enforcing the High Hedges Law. "a person authorised….may enter the neighbouring land in order to obtain information required by the appeal authority". Think you're going to stand your ground when they break out the measuring tapes? They have something for you. "A person who intentionally obstructs a person acting in the exercise of the powers under this section is guilty of an offence and shall be liable, on summary conviction, to a fine not exceeding level 3 on the standard scale". Level 3 appears to top off at 1,000 pounds (roughly $2,000).
I suppose I shouldn't be surprised by this. The sun set on the British Empire (and the freedoms it secured) a long time ago.