Any other else got an alert email stating that "You sites are receiving large number of fake impression and click.Stop it otherwise your sites will be blocked."?

I'm a bit confused on how they check it. I'm currently using coinmedia, bitcoset, cointraffic and coinzilla but I didn't receive any complaint from them regarding that fake traffic thing. 

https://snag.gy/nbDo2W.jpg Here's my stat for 4 days and I think nothing is suspicious on that stat since I'm using 5 adcodes each site that have almost 5k active users. https://snag.gy/pC7EB2.jpg