First, Hamas reacted by saying that the PFLP was taking advantage of all those wonderful freedoms that citizens of Gaza enjoy by daring to say something truthful. Or, as they put it,
[The PFLP] exploited the vast area of freedoms granted in the Gaza Strip. The timing of this statement does not serve the interests of the Palestinian citizen, but is consistent with all the voices of tension in the air and meant to turn the public opinion [against the government.]
Then Hamas raided the PFLP headquarters and arrested a number of leaders of the group.
Hamas' definition of "freedom" in Gaza seems to be "the freedom to do whatever Hamas demands."