Richard MacManus over at ZDNet takes a look at Mashups: who's really in control?. In particular he opens by emphasizing that:
In the mashup ecosystem, let's get one thing straight. The data owner is ultimately in control, because a mashup developer is reliant on data owners to keep the supply of data flowing.
Sometimes data services that were open to begin with, then have restrictions imposed on them. Or the data services may even be taken away completely, if the owner of the data decides they don't like what the mashup does to their bottom line.
Indeed, the power resides with the data and API providers. Sometimes this leads to calling the attorneys in. One of things I'll be putting together is a list of mashups that have run into legal trouble, either with the owner of data such as when craigslist booted Oodle, or with copyright or trademark violations as happened with Hasbro vs. Risk on a Google Map.
This is going to be a long running strategic and legal balancing act.