Herbalife does this, Ackman says, by targeting the financially vulnerable and unsophisticated, including stay-at-home moms, minorities and college students.

FORBES: Bill Ackman Takes on Herbalife

The Bank says that a fifth of British companies have become financially vulnerable.

ECONOMIST: The economy

That can leave you financially vulnerable, especially if you have to find a new place to live and are incurring moving expenses.

FORBES: The Financial Risks Of Leaving Your Spouse

From Ackman, perhaps his website could begin to highlight not just Herbalife, but other multilevel marketing companies that appear to prosper by appealing to financially vulnerable people.

FORBES: Bill Ackman Takes on Herbalife

Dr Katherine Rake from the institute said grandparents were not just expected to care for their grandchildren, but they were also increasingly having to support their adult children as well, as many were divorced and financially vulnerable.

BBC: UK 'behind' on grandparent childcare provision

"I was in a vulnerable place financially, " Hamlin says.

FORBES: Con.com