[epub] Trade mark violation?

[Dianne Reuby <d.reuby@xxxxxxxxxxxx>]

Hi all. I got this email today:
> Dear
> Web site Owner,
>  it has come to our attention that
> you are listing one or more articles by Kendall Summerhawk
>  which include mentioning 'weekly
> marketing wisdom'. 
>  S.R. Haden Industries owns the web
> site and service marks to the term
>  'weekly marketing wisdom'. Kendall
> Summerhawk and any sites she has her articles on
>  are in violation of U.S. Trade
> Mark / Service Mark laws.
>  We ask that you immediately delete
> these articles which are in violation of our rights
>  to that service mark :
>  http://www.firstwebbuilder.co.uk/startmarketing.html
>  We thank you for your cooperation
> in this matter.
>  Yours Truly,
>  Trade Mark / Service Mark
> Enforcement Department
>  S.R. Haden
> Industries

The page in question has an article (which I have permission to use) by
Kendall Summerhawk. Can the phrase "weekly marketing wisdom"
really be trade marked? Surely it's too general a term for that. I'm in
the UK, but presumably any US trademark laws would be
international.

My main question is really - how far should we go in checking out
articles supplied by the article banks?

Have a good week all,

Dianne Reuby
First Web Builder
http://www.firstwebbuilder.co.uk
Swindon Virtual Office
http://www.swindonvirtualoffice.co.uk
Free Site Builder
http://www.freesitebuilder.co.uk