Freedom of Information legislation has been introduced but critics say it does not go far enough in challenging official secrecy.
Meanwhile, the growth of the internet and advances in technology have thrown up new questions about how to protect individual privacy. BBC News Online looks at the issues.
Do the police and MI5 need a warrant every time they install a bug or a telephone tap? If so, how do they go about it and what do they need to prove?
Yes. Under the Regulation of Investigatory Powers Act 2000 the police and security services need a warrant, signed by the home secretary, before they can initiate a phone tap.
Sometimes, if there is an immediate threat to life or another reason for great urgency, taps will be initiated without a warrant. But the police must inform the home secretary as soon as practicable and obtain a retrospective warrant.
The warrant must name either a specific named person who is the target or a single set of premises which is the focus of the investigation.
Is it legal for private individuals or companies in the UK to tap phones or conduct covert surveillance?
No. Only a small number of law enforcement and intelligence agencies are permitted to tap other people's phones. It is legal to tap your own phone or those of your own company, but not somebody else's phone.
What clues would alert me that my phone might be tapped? How would I go about checking my home for taps or bugs?
If your phone is being tapped by a professional then there will be no clues.
But if they are amateurish, or are using obsolete equipment, you may hear clicking or tapping noises on the line. Some people have also heard previous conversations being played back down the line, or voices whispering.
To check for taps you can apply certain professionals who, equipped with the right equipment, can conduct counter surveillance sweeps to locate and remove bugs and possibly taps.
Is there any way I can find out if my phone is tapped, or my house bugged by the police or MI5? Can I find out if they have a file on me and, if so, what it says about me? Can I challenge what information is in these files?
No. Neither the police nor the intelligence services are under any obligation to reveal the presence of a bug or tap and would be foolish to admit to either.
In 1998 the then Home Secretary Jack Straw said, in a written parliamentary reply: "It is a clear principle of law and practice that people are never told whether or not their communications have been intercepted under warrant.
"The purpose is to safeguard operational practices and techniques from disclosures which might undermine their effectiveness."
Under the Data Protection Act you are entitled to request personal information about yourself. But the police and intelligence services will probably refuse under national security or law enforcement exemptions.
When does the Freedom of Information Act come into force and how will it change the way people can get access to information about themselves or things which affect their lives?
The act is being phased in but will be fully implemented by January 2005.
For the first time the press and public will be entitled to access the majority of information held by public bodies, including health trusts and education authorities.
The legislation is retrospective, so you can find out about records dating back to the 19th Century.
Public bodies will be entitled to charge for some information, to cover administrative costs, and certain information will be exempt. The information commissioner will have to adjudicate on exempt material.
Does the Freedom of Information Act affect companies and, if not, how can we find out about the firms who employ us or provide services to us?
Companies are not covered, although certain firms who work in the public sector - such as Railtrack - may be included.
Does the Act give me, or the press on my behalf, new rights to find out information about my new neighbours, my child's teachers, prospective childminders or potential business partners?
No. Personal information on individuals, which is held by public bodies, is exempt under the Data Protection Act and you would only be entitled to view it in very rare circumstances.
How much information about the government is kept secret?
A lot of sensitive political information, such as the minutes of Cabinet meetings, remains secret under the 30-year rule. Sometimes, for example with defence information, the time limit can be extended.
At the end of the 30 years they are released by the Public Record Office in Kew, south west London.
Under the Freedom of Information Act there is a wide-ranging exemption covering "policy advice", which has been widely criticised.
For example, with the foot-and-mouth crisis, ministers will not have to reveal the scientific advice, research or opinion polls on which decisions were based.
How does Britain compare with other countries in terms of secrecy?
Britain compares poorly with many other western countries, such as Sweden, which has had wide-ranging freedom of information legislation since the 19th Century. New Zealand and Ireland are also examples of good practice, although the latter's laws have recently been amended and access to information is not as good as it once was.
But some countries, such as Russia, China, Iran and North Korea have an almost paranoid fear of openness.
Many developing countries, such as the Democratic Republic of Congo, have got no process for allowing access to records. Their record-keeping tends to be "appalling" and many files go missing, or are burned, during times of conflict.
Is there any way of finding out if I am on a credit blacklist, and if so, is there any way of removing myself from it?
Under the Data Protection Act you are entitled to this information and, if you feel it is unfair, you can complain to the office of the information commissioner.
Has the internet changed things for the better or worse?
One of the negative aspects about the internet is that if criminals can crack a credit card database they can get tens of thousands or millions of useable numbers that would otherwise take them years to amass.
You should not send credit card details in an e-mail for the same reason that you would not put them on a postcard.
When you use a credit card online the information should be encrypted.
But the risk is that the firm you are buying from will not protect its database.
It is very easy for the police and intelligence services to intercept e-mail.
Technologically it is child's play. The hardest part is getting permission to do it in the first place and new laws make it much easier for the police to get surveillance requests approved.
But the police are only allowed to look at who you are communicating with rather than what you are talking about. If they want to look at the content of your e-mails they have to seek permission from much more senior judicial figures.