Yozzer,
Whilst I can sort of see your point is. There is a world of difference between a trust which charges admission fees so that it can continue it's preservation work and an exhibition in which the aim is to sell work for the benefit of the artist or owner of the pictures. When it is purely an exhibition of an owners collection of paintings/prints where the money goes to an organisation that reinvests money into a venture that directly benefits the industry as a opposed to an individual or company, then I don't see the problem of posting a link. Mods may obviously have a different view.
DeepC