They will say the same messages every game, like before diablo kill they will say “diablo kill # 243” or something like that. Once in the game it’s really, really obvious when someone is botting. For example, “!visit d2stationcom today for best deals!” They will load like 3 runners into the game and nonstop spam this type of stuff to get around the spam filter blizzard implemented 3 years ago (which worked for a while, until spammers found this method). This is only counting public bots (a lot of them advertise their websites via the “!x” command. This is due to the way bots create successive games.
You can tell because they have a “-xx” at the end of the game names, like “gz cbaal-19”. Out of the USEAST NonLadder games list, about 95% of them are bot games.
It wouldn’t take much for people to get the message. While I appreciate a blue response on this issue finally, I would suggest Blizzard themselves do the investigations and banning.