I've noticed some confusion over portkeys and their use. On this site, in particular, Why was the Triwizard Cup used as the portkey?. The question Barring legal issues, why aren't portkeys used more often? clearly identifies ministry regulations as one of the major factors in deterring use of portkeys and logistics as another deterrent for mass transportation. But how does the ministry enforce its regulations.
We know Dumbledore can circumvent this rule and makes unauthorized portkeys on multiple occasions: After Arthur's Attack, and to help Harry in leaving the Ministry in OoP after the duel with Lord V to name two.
As far as we are aware, Dumbledore is the only wizard to break this rule in the books, (I believe) and although he does so easily (and apparently receives no more consequence than Fudge's admonishment. The only possible exception to this is the creation of the portkeys after the seven potters to return everyone to the Burrow. There is some question as to whether those were unauthorized or not. If they were not authorized, then Dumbledore is not the only one to circumvent Ministry regulations and their enforcement.
"Now see here Dumbledore!" said Fudge, as Dumbledore walked over and picked up the golden head "you haven't got authorization for that portkey! You can't do things like that in front of the Minister of Magic!"
Order of the Phoenix Chapter 36 (pg. 818 in the Scholastic edition from 2003)
As usual, Dumbledore makes things look pretty easy, but there is another example in Order to prove breaking this rule is no easy task.
"How're we getting - wherever we're going?" Harry asked.
"Brooms," said Lupin. "Only way. You're too young to Apparate, they'll be watching the Floo Network, and it's more than our life's worth to set up an unauthorized Portkey."
Order of the Phoenix, The Advance Guard, Pate 52 (Scholastic:2003)
In the example above, there were a number of highly capable wizards present, Lupin, Moody, Shacklebolt, . . .
Is there any information in Book Canon I am missing, interviews with Rowling herself, on Pottermore or other sorces (that use citations - wikia doesn't work for me) that would help clear up what kinds of protections were placed to prevent the use of unauthorized portkeys and whether this applied only in England or everywhere?