When this scam was popular in the early days of the internet it was usually with foreign country code domains namely Chinese but now the scammers seem to been targeting global domain such as .net .org etc

This is a very common well known scam, but not a particularly dangerous one. The idea is to persuade you to register a number of overpriced domain names that you don't need. It's covered in the Wikipedia article on domain name scams under Fake Trademark Protection, and a HoaxSlayer page, Domain Name Application Scam

You usually get a email from an offical sounding domain name registration company that goes something like

We have received a request for the registration of the website www.yourdomain.net. Our system shows that you are the owner of www. yourdomain.co.uk.  This can have far-reaching consequences for you in the future. We are therefore under the obligation to contact you, in order to offer you the first right of registration. This means that we will reject the application of the third party and the website:

They use terms like far-reaching consequences to make you think that if someone else buys this domain that is similar to yours then you or your company are going to have problems.

All they want you to do is hastily click on their link to purchase this domain name at a highly inflated price sometimes 10 or even 20 times the going rate, leaving people with a domain name they don't needs and £100's of pounds out of pocket.

These scammers will sometime use clever wording too to make you think they are registering the domain for 10 years just to explain away the high price, when in reality it's 100's of pounds for a years registration, for a domain name that you don't need that would have only cost you £10.00 anyway.

This new batch of scams is coming from a company call www.dnsuk.org which has already been reported to Action Fraud....

If you get one of these scam email ignore it, if you want to help protect other then report it to https://www.actionfraud.police.uk/scam-emails so the site gets shut down ASAP