While obtaining a signature on an informed consent form is crucial, it is just but a step in the process of obtaining informed consent. As such, researchers should not put a lot of focus and emphasis on making the people sign the form. They should ensure that the people they are obtaining consent from understand the aim of the study and are willing to participate in it. Purpose, potential benefits and risks of their involvement, and the alternative options for such individuals should thus be made known to them. I agree with alexandrabuga that patients reserve the right to choose what can be done to their samples/data. If a patient decides not to sign a consent form, their decision should be respected even if not consenting would be a disservice to a community.
With regards to the HeLa cells, I am of the opinion that Lacks family should have received compensation. Under the current laws, failure to obtain informed consent is punishable, and if a patient chooses to check “No”, then that is it—no parts will be taken from their bodies for the purposes of research.