Tech companies usually can’t be sued merely for allowing people to post problematic content, but in the coming months, the court will consider whether that immunity extends to posts that the companies themselves recommend. The Supreme Court’s decision to hear the “targeted recommendations” case landed like a bombshell in the tech industry Monday because the high court has never fully considered the question of when companies can be sued for material that others post on online services. The immunity granted by lower courts under Section 230 has helped make possible a whole generation of internet companies, from review sites such as Yelp and Glassdoor, to news websites that allow user comments, to social media companies that let people post more or less freely.