Spam-transactions on Coinbase

I have heard about spam-transactions on Coinbase. Is it true? And what consequences would be happen to me and my funds on this exchange platform? Would you please to tell me for what this false activity is organized? I am very interested in it because my everyday money turnover on this exchange is something about 50 dollars. I don’t want to have any problems with this platform and take many risks. Maybe it would be better to find any other platform. So what are you think, guys?