A Yahoo spokeswoman declined to comment about the lawsuit, or whether the claim that only 4 percent of the fund had gone to imprisoned dissidents was accurate. The case is the latest headache for Yahoo, which is expected to complete a roughly $4.8 billion sale to Verizon later this year. The deal, reached last July, marked a low point for Yahoo, once a $125 billion tech behemoth as big Google or Facebook are today.