Virtual Earth update – In world advertising

Today's Virtual Earth update sees the inclusion of in-world advertising, powered by Microsoft's acquisition earlier this year of Massive Inc. Though Massive's technology is mainly used to include advertising in games, usually from large corporations, this horizontal step into Windows Live Local provides a wealth of advertising opportunities for smaller businesses.
Combining Massive's technology with "Call for Free" – another Live Local feature that allows consumers to be called back by advertisers if they want more information on a service – gives Windows Live a powerful and perhaps almost unexpected, monetisation platform. It actually resembles an approach adopted by some players in Second Life, the online virtual world.
Two issues regarding this development is whether negative, or disruptive advertising will be allowed, and if there are any legal lssues concerning advertising on a virtual representation of other people's property.