Prime Minister David Cameron has said he feels "uneasy" about judges granting injunctions to protect the privacy of powerful individuals.
He argued that Parliament, not judges, should decide on the balance between press freedom and privacy.
The courts are using human rights legislation "to deliver a sort of privacy law", he warned.
His comments follow a number of recent injunctions which have banned the identification of celebrities.
Mr Cameron was challenged about the use of injunctions during a question-and-answer session at the General Motors factory in Luton.
He said: "I think there is a question here about privacy and about the way our system works.
"I think we do need to have a proper sit back and think: is this right?
"What ought to happen in a parliamentary democracy, is Parliament, which you elect and put there, should decide how much protection we want for individuals and [on] freedom of the press and the rest of it."
But Mr Cameron admitted he did not have all the answers and that he needed to think some more about the issues.
'Out of hand'
Vanessa Perroncel, who successfully forced two British newspapers to apologise after they alleged she had an affair with the then England captain John Terry, told the BBC that injunctions were being issued too frequently.
Mr Terry won an injunction to suppress the story but it was overturned.
"I think it's getting out of hand," Ms Perroncel said. "Obviously it's a very expensive thing to do. [Injunctions are] only there for the rich, really. I guess they can have this luxury."
On Wednesday, High Court judge Mr Justice Eady agreed to issue a "contra mundum" order - effectively a worldwide ban - in the case of a man who sought to prevent publication of material about his private life.
Such orders were previously used to stop the publication of details about the killers of James Bulger, when a court ruled that there was a "strong possibility" that their lives would be at risk if they were identified.
A contra mundum order is intended to apply forever, and applies to everyone - as opposed to forbidding the publication of details by a specific newspaper or journalist.
Giving his reasons for making the order, sought by the claimant at a hearing on 6 April, Mr Justice Eady said the High Court had the power to stop anyone and everyone from publishing material to protect an individual's rights.
He said this power could be used "wherever it is necessary and proportionate".
In a separate case, a married Premier League footballer who reportedly had an affair with Big Brother's Imogen Thomas won the right to continue his anonymity.
The decision is seen by many as another step in the move by the courts to extend protections for the right to respect for privacy and family life under Article 8 of the European Convention on Human Rights, to which the UK is a signatory.
But it also marks a further advance in the steps the courts are prepared to take in restricting the right to freedom of expression under Article 10 of the Convention, whose principles were incorporated into British law through the 1998 Human Rights Act.
The law firm Carter Ruck, which has represented famous figures seeking injunctions, defended the practice.
Carter Ruck managing partner Cameron Doley said that injunctions could be obtained by people who were not rich and they were not there just to help the powerful suppress scandals.
And he argued that "genuinely private people" had a right to protection.
Liberal Democrat MP John Hemming has criticised the cost of contesting an order, describing the system as "unbalanced", and one that can be won by money rather than arguments.
And the head of the Commons Culture Committee, Conservative John Whittingdale, said MPs were "concerned " about the growing number of injunctions given that Parliament had stated, when considering the passage of the Human Rights Act, that it was not in favour of a privacy law.
"Parliament was very clear that the right of freedom of expression should be given greater weight than privacy and there need to be very strong grounds for a privacy injunction to be granted," he told the BBC News Channel.
"There is a section of the Human Rights Act that should be telling the courts they need to apply a higher bar before granting a privacy injunction."
But Mr Doley said that, since the cost of obtaining an order could cost in the low tens of thousands of pounds, it was within the reach of people who were not rich or famous.
"They may be professional people like doctors and lawyers who have some prominence but are not household names like John Terry."
PR consultant Max Clifford said: "The privacy of the rich and famous seems to be exactly what the courts are determined to achieve.
"What we've got in this country now is a privacy law that wasn't brought in by Parliament but the judges have decided what they want and that's what they've achieved."