The clearest example is from the LWN article you referenced.

> "Once a developer assigns copyright, they are at the mercy of the assignee to enforce the copyright. In this particular case, one can speculate that the failure to pursue the violation was likely a shortage of human resources. As Richard noted, "We have staff for GPL enforcement, […] but there are so many violations that they can't take action on all.""

As the LWN article notes, statements like this are a huge distance between FSF in practice, and FSF's own reasoning behind assigning copyrights to it (http://www.gnu.org/licenses/why-assign.html).

When a project has assigned copyright to FSF, the project workers have no recourse when the copyright holder opts not to fulfill its part of the bargain.