Is a company morally responsible for the misuse of a legitimate and socially useful product of their manufacture?
This is, to a great extent, a matter of opinion. My own view is that no firm is morally responsible for the misuse of its product as long as two conditions are met.
First, the firm needs to do everything that is economically feasible to make sure that its product cannot be misused. For example, if there is company that makes pseudoephedrine, that company should make it as difficult as possible (without making themselves go out of business) for people to use its product to make methamphetamine. They should, for example, sell their medicine in blister packs rather than in bottles so that people would have to take the time to push out each individual pill from its blister pack rather than being able to pour entire bottles into their cooking operation.
Second, the firm must clearly not try to profit in any way from the misuse of their product. For example, let us say that we have a football team whose clothing is popular among gang members. The team should not do anything like marketing styles of clothing that are meant to appeal to gang members. The team cannot prevent gang members from using its apparel, but it should not try to make money by catering to those gang members.
I do not think that firms can possibly be held responsible for the improper use of their products if they meet these conditions.