Just to put in some personal experience into the discussion: We actually did monitor my kids secretly with a Keylogger, due to my wife bragging and nagging about to do it. Technically it worked perfectly, we used a software called Wolfeye Windows Keylogger and it recorded every keystroke and took regularly screenshots, sending the data to wifeys email... So she could follow thoroughly. I say technically and used as it caused, as I was expecting it, quite an issue and moreover a lack of trust after one of our boys found out about it... So whatever you do, do it openly, talk and explain, it will be the better solution. Not to mention that in the end you may always lose, if there is nothing happening at all, there is still a trust breach, and that will be broken also if there is something going on and you need to intervene. So no matter how good your monitoring software is, it will not solve the topic. Only trust and talking will do the job of securing your kids online activities.