Many universities have been slow to react to evidence about the extent of the practice.
Now a prominent consumer group has tried to document the extent of the practice.
No overall figures are available, however, to show the extent of the practice.
Clarke highlights the extent of the practice of rotational heather burning on grouse moors, widely used to increase the number of red grouse available for recreational shooting.
It took Mr Lawsky's well-staffed unit a year to figure out the extent of the practice in his state.
The Press Complaints Commission is to investigate allegations of phone hacking by News of the World journalists in the light of new evidence uncovered by the Guardian about the extent of the practice "without delay".
Pitchford is seeking to investigate the full extent of the practice by police forces in England and Wales, as part of his inquiry into how undercover officers have spied on hundreds of political groups since 1968.
Save for the evidence relating to the Mirror titles which has already been examined, it is not possible, and indeed is unnecessary, to seek to identify particular titles or to quantify the extent of the practice.
It is the sheer extent of the practice described as "revolving doors" (a misnomer since it is mostly one-way, that is, from Whitehall to private companies) that makes it so important.
The men have testified that they told James Murdoch in June 2008 of the extent of the hacking, but Mr. Murdoch has said he did not learn of the extent of the practice until last year.
The summary of the notebooks might finally show the full extent of the practice, which Mr. Murdoch's British newspaper company, News International, insisted for many years was the work of one "rogue reporter".
