They can if you operate in a regulated industry, such as pharma, med devices, cannabis, dietary supplements, etc.

FDA has specific labeling requirements for products and they look at hashtags related to products the same way they evaluate other written labeling.

For example, FDA sent a warning letter to a cannabis company because it misleadingly represented certain CBD products as safe and/or effective for the treatment or prevention of COVID-19. In making this finding, FDA looked at the company's Facebook page and noted a link captioned with the tags “#covid19cbd” and “#cbdcoronavirus.”

Not only does FDA take issue with the tags, but FTC also finds it unlawful to advertise a product can prevent, treat, or cure human disease unless you possess competent and reliable scientific evidence, including, when appropriate, well-controlled human clinical studies, substantiating that the claims are true at the time they are made.

If you are operating in a highly regulated industry, make sure that your social media directors and marketing team understand the legal requirements. These are special products and the claims made about them must be vetted even if they are the #bestproductsever.