As the title of this thread implies, you've never had one, have you? So let me answer your points:
"how easy is it to get the IDT Prime card: very easy just had over the cash and its yours" - Indeed this is true and its the biggest selling point, but what are you buying? - A one time disposable card with a maximum value of £150! Which answers your next point:
"do you need to provide ID: hell no. this means that it can be used by criminals to hide the cash they steal also terrorists can use this to buy goods for their activates" - A one time disposable card does not require ID but with a £150 limit I think the terrorists are going to struggle when financing their multimillion dollar activities!
In fact (as you would know if you had a card as opposed to listening to general hearsay) if you want to use the card on a regular basis and top it up and put a few thousand pounds on it, you need to upgrade (£1.95) which involves doing an identity check (sorry terrorists).
And finally:
"is there an lower age limit (eg 18/13): Nope, this can be used by minors to get access to adult content" - Well lets look at their T&C's which is on the website:
"1.8 Only persons over 18 years of age are entitled to purchase the Card. Once purchased, the Card may be given to another person, including a person under 18 years of age. However, Transactions by persons under 18 years of age may not be allowed by some Merchants."
Now lets understand this, its clearly written on the back of the packet that it can only be purchased by over 18's and the shops themselves know this. If a shop sells the card to someone under 18 it is illegal and the same as them selling alcohol or cigarettes to uderage kids.
They allow an adult to give the card to someone under 18, however, once notified the card is switched to teen blocking i.e. it cant be used to purchase or view things only meant for over 18's.
I hope all this info answers your questions. If you have any more things you would like to know, from someone who actually uses the card, then feel free.