the "One group" in question is Hebrew University in Israel. So not exactly a sue-happy small group so much as a super well-funded very large organization.
Sure, but even if they really want to own that and disregarding how good their lawyers are copyright law has a hard deadline. Einstein died 76 years ago, it should be public by now ... right?
These are personality/publicity rights, not copyrights. They are much closer to trademarks in their purpose. In the US they are governed by state law and in some states they don't expire until 100 years after a person's death.