Yes and no. When stymies were permitted, a player could mark and lift his ball if it lay in his adversary's path to the hole if and only if the two balls lay within six inches of each other. When the stymie was outlawed, then of course any ball lying in another's path to the hole could be marked and lifted. And you are obliged to so so in consideration of the other player since as you are probably aware, striking another ball on the green these days when putting incurs a two stroke penalty.
You mentioned the movie The Greatest Game Ever Played. It may interest you to know that Bernard Darwin (my namesake) was Francis Ouimet's marker in that game and is portrayed as such in the movie.