Germany's highest court ruled on Wednesday that a telephone tapping law in the state of Lower Saxony was unconstitutional, dealing a blow to police investigators.

In a decision that weighed personal freedom against security in the age of terrorism, Constitutional Court Chief Justice Hans-Jürgen Papier said that "security laws that allow government tampering limit personal freedom and can, in extreme cases, alienate citizens."

Police investigators had argued that the law, which allows tapping of phones even when there is no suspicion of criminal activity, is an important tool in the anti-terror fight. The decision is a victory for civil rights activists, who are worried that recent terrorist attacks in London and Sharm al-Sheik could lead to increased security measures at the expense of personal freedom.

Success breeds imitation

Such measures could come sooner rather than later in cities across Europe. Based on the success video survillance equipment has had in helping London police track down terrorism suspects linked to the recent bombings, several European governments are mulling more aggressive public surveillance measures.

In France, Interior Minister Nicolas Sarkozy announced on Monday that cameras would be installed by the end of the year in more than 4,000 buses. Sarkozy also said an anti-terrorist law, containing plans for video surveillance and collection of telephone data, would be introduced to parliament after the summer recess and is expected to be adopted before Christmas.

In Germany, the city of Berlin and the regional government of Brandenburg have announced plans to add cameras to the existing network covering public transport and to maintain an older archive of video footage.

"After the attacks on the British capital, we don't want to be criticized for not adequately responding," said Berlin public transports company (BVG) chief Thomas Necker.

Rome, Moscow promise more and better cameras

In Italy, which has been regularly threatened in Internet messages by groups claiming links to the radical Islamist organisation Al-Qaeda, a million surveillance cameras are already in place and the government has decided to install more and of better quality, particularly in the Rome metro.

The London attacks, which killed 52 people and the four suicide bombers on July 7 on the London Underground system and a double-decker bus, have also persauded Moscow to install a network of video cameras in its metro system:

"Within a year and a half every carriage of the metro will have one", said the head of the Moscow metro Dmitri Gaiev.

Surveillance of mobile telephone networks, which will allow authorities to identify callers, receivers and locations, will also be reinforced. A number of governments, including France, have asked mobile telephone network operators to archive all these elements for a year, while stopping short of taping conversations.

More police control over mobile phones

Similar measures are also being considered by Spain, where police would also like to remove the anonymity of the 24 million Spaniards and residents, who use pre-paid mobile telephone cards.

This type of card was used by the bombers of the Madrid suburban rail network in 2004.

Mobile telephones were used to set off the bombs used in those attacks in which 191 people died. Last week, the Italian government brought in a new regulation which requires people buying computer chips for mobile telephones to provide proof of identity.

Greek minister for public order George Voulgarakis has asked mobile network operators to establish procedures to provide police with rapid access to mobile telephone call information and called for European legislation which harmonises this type of system across the continent.

The introduction of biometric passports, which use physical identification markers such as fingerprints or eye scans, will also be accelerated following the London bombings. The European Union has already said these types of passports will be obligatory within three years.

Scandinavian countries staying the same

In most countries the opposition to these types of security measures is facing an uphill battle following the two sets of bomb attacks in London and the latest attack on the Red Sea resort of Sharm el-Sheik in Egypt, which killed 88 people last Saturday.

In Italy, an opinion poll published ten days after the London bombings found that 74 percent of those surveyed were in favor of more security cameras in public places and 60 percent support tighter surveillance of electronic messages.

However there remains opposition to this increased government intrusion into people's private lives. In Denmark, a country often threatened in Al-Qaeda statements on the Internet, a bill to increase police powers of surveillance was rejected by parliament.

"The citizens must be able to move around in peace," said ruling Liberal party spokeswoman Birthe Roenn Hornbech. In Sweden, which has far less video surveillance of public places than Britain, a recent study concluded that the current system works well and does not need to be expanded, according to justice ministry advisor Maria Kelt.

"One change that was suggested was that police should be able to use video surveillance without getting a permit," she said.