Public goods are by definition non-rivalrous and non-excludable. How can they be gobbled?

https://en.wikipedia.org/wiki/Public_good_(economics)

(I'm not being pedantic here. The concept of a public good, in this technical sense, is a very important concept to have -- and it's specifically the kind of "public goods" the article was talking about, along with ideas for improving their tendency to be under-supplied. Goods that can be gobbled up by someone tend to be produced at closer to the optimum amount, since there's a less diffuse private incentive for their production.)