Doing research online, via Zoom, Teams, or live chat, is becoming more and more common. It can help researchers to reach more people, including from different parts of the world. It can also make the research more accessible for participants, especially those with different communication preferences. However, online research can have its downsides too. We have recently been involved in three studies in which we had in-depth discussions with autistic people and/or parents of autistic children about various topics. It turns out, though, that some of these participants were not genuine. Instead, we believe they were "scammer participants": people posing as autistic people or parents of autistic children, possibly to gain money from doing the research. This is a real problem because we need research data that we can trust. In this letter, we encourage autism researchers to be wary of scammer participants in their own research.