what do you think do they go overboard on the mature tag to much on online readers

Any examples? I don't use online readers at all these days.

I agree an example would be nice; however, I think the mature tag is appropriate in alot of cases. For example,

Quote from daed

i just finished koroshiya ichi the other
i completely dont recommend it if your squeamish at all
i thought i was open about violence and murder from movies and tv
but wow

im still got the "completely shocked" look on my face
what was the deal with

cutting off everybody's nipples?

As daed shows, there is a fair portion that involves the portrayal (often by villains) of pretty serious war-crimes. Crimes ban by the UN because they are historically known to be the precursors to total war or civil war. The manga community and industry at some point must self regulate if it expects to continue to draw interest from new members/public. What that self-regulation entails is of course really up to them.

I agree they do go overboard sometimes but I think the fact they let pretty much anyone edit the tags leads to false labeling.