SIDAMO and HARAR are coffee growing regions in Ethiopia. It appears that those terms are widely used to refer to the beans grown in those regions. The Government of Ethiopia filed U.S. trademark applications for those terms. As far as I can discern from the PTO website, these are registrations for ‘regular’ registrations on the principal register and not for certification marks.
The applications have met descriptiveness objections (as the examiner turned up ample evidence of the terms being used not as trademarks but as descriptive terms). Additionally, Letters of Protest have been accepted by the PTO and communicated to the examiner, providing evidence that the terms are generic. As a procedural aside, a Letter of Protest is not an inter partes proceeding. It is an ex parte communication from a third party that is examined by the PTO before the information in it is provided to the Examining Attorney. I had trouble opening these massive (600+ pages) PDF documents on the PTO site, but they appear to contain evidentiary material about generic use of these terms.
Oxfam has now criticized Starbucks, alleging that Starbucks influenced a coffee trade association to obstruct the applications, and that the loss of these trademarks will cost poor Ethiopian farmers tens of millions of dollars. Some articles claim that Starbucks or the trade association has opposed the applications, which is not correct. I assume that it was the trade association that filed the Letters of Protest.
Starbucks has responded to Oxfam’s allegations.

One thing that is not clear to me from the printed reports is why these applications are for conventional trademarks and not for certification marks.
I think we would need to understand the economics of the SIDAMO and HARAR bean markets to appreciate precisely what is going on. The proposition that opposing trademark protection hurts the Ethiopian farmers would be supported by two different arguments. The first is that the existence of the trademarks (any type of trademarks) for these names, would benefit the farmers because it would allow the trademark owner to police against beans grown outside of Ethiopia from using those names.
The second argument is a two-edged sword. Anyone who owns these marks will be able to cartelize the growers, for better or worse. If the names are owned as trademarks by the Ethiopian government, or, if the names became certification marks where the certifying procedure was controlled by the Ethiopian government, then the government would be able to control which growers in those regions could use the terms. The Ethiopian government might be able to prevent certain growers from using the terms, even if they grow beans in those regions.
Ownership of geographical terms as conventional trademarks have resulted in attempts to prohibit truthful (but competitive) use of the term as a geographic indicator, so the fear that growers within the regions may not be allowed to use the terms, would not be unfounded (see disputes relating to CHIHUAHUA cheese and TILLAMOOK cheese).
Here is the US PTO’s discussion of geographical indicators and certification marks.