You don't even need a screenshot for that. Any text online, even just a comment will be taken at face value by a certain percentage of the population. The general gullibility of people or their susceptibility to disinformation is always going to be an issue. Even for people like that who just don't question things they see (especially when they want to believe them) I'd bet if you pressed them they'd admit to being aware of photoshop and of just how easy it is to fake a screenshot of text.