As we have learned, one who performs a melakha on Shabbat be-shogeg may benefit from it immediately after Shabbat, as may other Jews. If he transgressed be-mezid, he may never benefit from it, though others may benefit from it after Shabbat. For example, if one knowingly cooked food on Shabbat, he may never eat it. Others, including those he cooked for, may eat the food after Shabbat (MB 318:5). Similarly, if one built a house on Shabbat, others may benefit from it after Shabbat, but he may never use it. However, he may sell the house to others (MB 318:4).
One who knowingly laundered his clothes on Shabbat may not wear them even after Shabbat, because one may never benefit from a melakha that he performed knowingly on Shabbat. A solution in such a case is to wash the clothes again during the week, after which he may wear them (Ben Ish Ĥai, Year 2, Vayeĥi 19).
If a non-observant Jew regularly performs melakha on Shabbat for other Jews, they may not benefit from this melakha even after Shabbat. Only when a melakha is done occasionally may those on whose behalf the melakha was done benefit from it after Shabbat, as there is no concern that they will ask him to desecrate Shabbat again so that they can benefit after Shabbat. However, if he does this melakha regularly, they may never benefit from it. For example, one may not buy bread from one who regularly bakes it on Shabbat in order to sell it after Shabbat, even if all the ingredients are kosher. Eating it encourages him to continue desecrating Shabbat, and they would take part in his transgression. Similarly, no Jew may eat at a restaurant where a Jewish chef cooks on Shabbat for customers who will come after Shabbat.
One may not watch sports games or other televised events after Shabbat if these events were filmed by Jews on Shabbat. Since the filming involved intentional Shabbat desecration on the part of the videographers for the sake of their viewers after Shabbat, the viewers may not benefit from this Shabbat desecration. The same applies to fruits and vegetables brought to market on Sunday. If it is known for certain that they were picked by Jews on Shabbat, no Jew may eat them.
Technically, one may buy dairy products from a dairy farm that desecrates Shabbat when milking the cows (see above 20:4), because the milk produced on Shabbat is mixed with the milk produced on other days. Thus, for any bag of milk that one buys, it is uncertain whether it was milked on Shabbat. Since the prohibition of benefiting from melakha done on Shabbat is rabbinic, in cases of uncertainty we may be lenient. This also applies to a factory that produces paper all week long, including Shabbat. Technically, one may buy its paper. Nevertheless, it is always preferable to buy products from factories and companies that observe Shabbat. If all Shabbat observers were to unite in order to strengthen Shabbat observance, it would be possible as a temporary measure to forbid any benefit from the products of factories that desecrate Shabbat (see Yalkut Yosef 318:72, 74-5; Orĥot Shabbat 25:57-61).