President Obama recently signed Executive Order: #13685  , in short this Order states:
(a) The following are prohibited:
(i) new investment in the Crimea region of Ukraine by a United States person, wherever located;
(ii) the importation into the United States, directly or indirectly, of any goods, services, or technology from the Crimea region of Ukraine;
(iii) the exportation, reexportation, sale, or supply, directly or indirectly, from the United States, or by a United States person, wherever located, of any goods, services, or technology to the Crimea region of Ukraine;
(iv) any approval, financing, facilitation, or guarantee by a United States person, wherever located, of a transaction by a foreign person where the transaction by that foreign person would be prohibited by this section if performed by a United States person or within the United States.
I spoke with an attorney about this because it directly affects my other interests. The attorney was apprised of the following:
* PGDG (PostgreSQL Global Development Group) is not a corporate or legal entity
* There are tangibly connected non-profits (SPI, postgresql.us, postgresql.eu etc…)
* That we are an Open Source community
* A detailed description of how Open Source and specifically the PostgreSQL community operates
There were multiple scenarios presented (the non-profits under their current methods of doing business are fine) but there “could” be a problem in the following scenario:
- Crimean developer submits patch to .Org
- United States based committer reviews patch
- United States based committer commits patch
- “possible” violation of Order #13685
I brought the specific example to the attorney because it is the most likely and even though there are other anomalies, this order currently has:
* No guidance from OFAC 
* The liability would fall personally on the committer
United States PostgreSQL is not offering legal advice but we are suggesting that if you are a United States based committer, you might want to consult your attorney about the implications of this Order.
It is “my” opinion that it is not likely that the justice department will be knocking on your door for committing a patch for a Crimean contributor, but I am not an attorney and stranger things have happened.