Clear explanation of Conflict of Interest with examples in journal articles

I recall having seen some papers (say, on a method of electrode modification), where an author has been a shareholder in a company implementing this method on an industry scale, commercially. This is an example of a COI; a person is gaining money from another entity (in this case, his company) working in the same sphere.

Here's what I found on the web.

A potential conflict of interest exists when an author has a direct or indirect relationship, through the research-sponsoring institution, with a company that may benefit from the results of the study. The following types of relationship are considered as potentially conflicting and must be disclosed:

If over the past two years one of the authors:

• Received fees for consulting services, delivery of lectures and text writing or payment for any other type of service rendered to the manufacturer of the product.
• Received any kind of contribution from the manufacturer of the product (funds for the project, equipment, drugs, personnel) related to the project under analysis or any other involving the same product.
• Received funds from the manufacturer of the product to participate in congresses/conferences.
• Owned stocks in the company that manufactures the product.
• Is employed by a company that may direct or indirectly benefit from the results of the study.
• The manufacturer of the product has been involved in data collection, analysis, interpretation or writing.

My example falls under 'owned stocks' part.

We turn to the medical literature, particularly hospital epidemiology, which has a lot of corporate funding relative to federal funding.

Example 1 (http://www.jstor.org/stable/10.1086/674394?origin=JSTOR-pdf):

E.T.L. has received research grant support from Merck. D.J.A. participates on the speaker’s bureau of and has received research grant support from Merck. All other authors report no conflicts of interest relevant to this article. All authors submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest, and the conflicts that the editors consider relevant to this article are disclosed here.

Example 2 (http://www.jstor.org/stable/10.1086/658944?seq=1#page_scan_tab_contents):

Potential conflicts of interest. E.R.D. reports that he has performed research for Viropharma and Merck and has served as a consultant for Merck, Becton-Dickinson, Optimer, Meridian, and Steris. All other authors report no conflicts of interest relevant to this article.

Generally speaking, the ICMJE asks about any sort of financial relationship that may be thought of as potentially influencing the results of the study, including board membership, consulting, expert testimony, grants, speakers bureaus, payment for manuscript prep., patents, royalties, stock, travel outside the project, etc.

It doesn't necessarily alter the review process, but reviewers are provided with the COI, and it has, in at least one paper I've read, put the results in context. I imagine for particular egregious examples, it could pose a problem. It's also a mandatory disclaimer at the beginning of almost all conference presentations in the field.