"In regarding the Kli that is referred to as internet which has caused many to stray from the path, and that the Chazon Ish zatzal ruled at the time on the issue of drafting and inducting women into the Israeli army that it falls under the category of " rather get killed than commit a transgression " and this kli mashchis (the internet) is much much worse( than the induction of women) and you can definately say that is also in the category of yehoreg val yaavor
Harav Mattisyahu solomon Shlita explained here at the aguda convention that we are talking about unfilltered internet. and the comparison to giyus banos is a strong one. Just as a lady can not put herself in a situation were she will be vulnerable even though the first step does not appear to be so bad. It also wont necessarily happen and there might a remote situation that will lead to yehoreg val yaavor still the Chazon Ish ruled that it is yehoreg vaal yaavor. So to by having unfilltered internet accsess one is vulnerable to all the aveiros in the world which has been proven and known to ruin hundreds and thousands of people chalila even inadvertently all it takes is the push of a wrong button.