e-commerce and data mining

Should online retailers or search engines be deterred from mining usage data from their websites, or from monitoring trends in how Internet users are using the Internet as a whole? Are there benefits to allowing an online retailers or search engine to mine data? If so, how far should these sites be allowed to go in terms of collecting personal data? When should they be required to stop?

Here are some articles relating to this discussion:

Wakefield, R., and Whitten, D. 2006. Examining User Perceptions of Third Party Organization Credibility and Trust in an E-retailer. Journal of Organizational and End User Computing, v. 18: 2.

Clark T. H. and Ho G. L. Electronic intermediaries: trust building and market differentiation, in 32nd Annual Hawaii International Conference on Systems Sciences, IEEE, 1999, Hawaii.