In 2000, during a periodic update of anti-terrorism laws, the UK Parliament enacted a now-notorious law. Section 44 of the Terrorism Act 2000 permits police to stop and search any person or vehicle in a designated area and seize anything they suspect could be used for terrorism. The law did not require any suspicion in order to initiate a search, and as a result it has been widely abused. It is now routinely used against political protestors, who can expect to be labelled "terrorists" and be arbitrarily detained and searched for speaking up about their society. It has been used against critics of the government, and against photographers. There were over 250,000 such searches carried out last year, and it seems to be becoming a regular and routine invasion of privacy.
Which is why the European Court of Human Rights just ruled it illegal and a violation of Article 8 of the European Convention on Human Rights. Article 8 affirms people's privacy and their right to be free of unlawful and arbitrary searches. And searches which require no grounds, which are widely carried out but result in virtually no arrests, and which are sometimes conducted solely to balance racial statistics certainly seem to meet that criteria.
The UK government is of course appealing, but it is difficult to see how they will win. "Search requires reasonable suspicion" is a fundamental rule in a decent society under the rule of law, and the UK law simply abandons this. Rather than stamping their feet like petulant little authoritarians, they should simply amend the law to require reasonable suspicion to conduct searches. But then it wouldn't be nearly so useful in intimidating and suppressing democratic dissent...