This petition is growing in support. A ban must be appropriately applied and yes we know fraudsters will always find a way around any obstacles put in front of them. 

Acting to stop these scammers being able to enter people's homes, be that by doorstep, phone, email of mail can surely only be seen as a positive step. 

Whilst those of us that think we are savvy and would never fall foul to a cold call we may have family, neighbours or friends that may just be caught out. A well publicised ban would help spread the word that should a cold call get through you are right to hang on up on that would be scammer!

http://www.grantthornton.co.uk/en/insights/investment-scams---asset-tracing--recovering-money/