My guess on this and that tw.t Fergus is that they, like all the other post 2002 BTLers are having their mortgages called in by the banks. Its called a Margin Call. Have a read of your mortgage T+Cs - the house is not yours until the bank is paid off.
It does not take a genius to see that the majority, if not all, of the banks who were active in BTL from 2002-2010 are either bust (NR, B+B) or in a lot of trouble (pretty much all the rest via their subsidary operation - MEX, etc).
It was total insanity of giving out multiple loans, often totalling several million to an individual FFS! With bugger all deposit!!!!
Can't remember the bad bank that had all this crap shoveled into it - UKAR (B+B + NR) thank you google.
UKAR has only been going for 4 years and has probably gone through the more solvent, 'nice' debt. Now it needs to to step up and go through the crap (Fergus') and be nasty (Fergus and this bloke probably).
The other banks appear to be following a similar process - asking for their money back.
If these people stick to paying the money due they are fine but one missed payment and the banks will put them in default.