Your photos remain yours only when they are stored in family photo albums! This follows from the opinion of the New York district court in the case of the applicant, Stephanie Sinclair. The point is that a professional photographer discovered that Mashable used her photos to publish on its website in a very unusual way in 2016-they were borrowed from her Instagram account.
Stephanie said that this information is blurred in the agreement. However, this, in the opinion of the judge, does not give grounds to claim that there is a violation of her rights. Moreover, some users (and probably most) do not read the agreements at all, blindly trusting the service developers. Such an approach is not only careless these days, but also unsafe. You should carefully study all the points. However, it makes sense to streamline the texts of agreements themselves and make them more understandable and transparent.
As for photos on Instagram, you need to make a choice for yourself – either publish them and know that they can be used by everyone who is not lazy or refuse to use the service at all. In contrast to the decision of the American court, you can put the verdict of the European court, when the judges recognized the need to obtain a license to use any photos found on the Internet.