There are 7 people dead, including the gunman, in a case of an unstable man whose twisted expectations of what he deserved to get from women went on a killing spree in retribution.
I could lament the societal conditions that have contributed to something like this even being possible (sex sells after all, and the cultural expectation to be able to "experiment" in your college with promiscuity has been cemented for decades), but instead I just want to give three things we can do individually that can positively impact our own worlds.
1. Don't take part in the objectification of women
Pornography is the most obvious form of objectification (from the most hardcore end of the spectrum to the "leering laddie" end), but it can be more subtle than that, too. For instance, this woman explains that she apologizes when not wearing make-up—as if her value is contingent upon her looks. I'm not certain what my response would be if a woman were to say that to me (I'd like to think that I'd protest her apology), but from now on I'll make sure my reaction reinforces her value above what she looks like.
2. Make it a point to compliment women on things other than their looks
Female family members and friends of mine have explained this to me before, and it makes a lot of sense. Our cultural tendency is to compliment girls from a super young age on how pretty they are, often leaving aside other accomplishments they may make. A lifetime of these compliments on both a macro and micro scale throughout our society would serve to reinforce those values; people tend to live up to the expectations that are set for them (which is why you see generational cycles, such as the cycle of poverty or the cycle of spousal abuse).
So make it a point not to follow that norm. Compliment young girls on their talents in school, their interest in reading or biology or astrophysics or LEGO. The way I think about this is, everybody else in the world will be continually telling them they're pretty, so there's lots of room for me to compliment the girls I know on anything else.
And when it comes to adults, whether it be strangers or friends, make your compliments (you are complimenting your friends regularly, right?) large in variety. Learn when to compliment on appearance, which is important, but learn how to do it well, at the correct time, and never at the expense of other genuine accolades.
3. Speak up if somebody you know expresses misogynistic attitudes
My mom is excellent at speaking up when somebody starts badmouthing another person in their absence (she always speaks up with praise about that person in their defense); doing so with specific regard to misogynistic attitudes is another small way to help counteract those attitudes in our own circles. If you're a guy hanging out with your bros at the pub and the conversation turns to women, speak up against any attitudes you may detect that objectifies or disrespects women. You may lose bro points or be the odd man out that night, but honestly, the sign of true manhood is the ability and willingness to stand up for what you believe in despite peer pressure.
Christians are expected to do this kind of behavior in everything they do (Ephesians 4:15 Ephesians 4:15But speaking the truth in love, may grow up into him in all things, which is the head, even Christ:
American King James Version×).
4. Do all these things out of love
I said I was only listing three things, but the fourth one is kind of the underlying foundational thing to remember all the time anyway. The motivation for everything we do as a Christian is love. God loved us so much that His son died for our shortcomings in order that we may live forever (John 3:16 John 3:16For God so loved the world, that he gave his only begotten Son, that whoever believes in him should not perish, but have everlasting life.
American King James Version×, 1 Peter 2:23 1 Peter 2:23Who, when he was reviled, reviled not again; when he suffered, he threatened not; but committed himself to him that judges righteously:
American King James Version×). Every human being is destined for that glorious life. Paul even wrote that being a Christian erases our physical distinctions, spiritually speaking (Galatians 3:26-28 Galatians 3:26-28  For you are all the children of God by faith in Christ Jesus.  For as many of you as have been baptized into Christ have put on Christ.  There is neither Jew nor Greek, there is neither bond nor free, there is neither male nor female: for you are all one in Christ Jesus.
American King James Version×explains why racism and bigotry is un-Christian, and likewise why degrading women is also ungodly).
So as a child of God, each woman is worthy of respect and honor. Us men must take it upon ourselves to protect that honor and respect. Both passively by not contributing to the culture of objectification but also actively by standing up against those attitudes when we see them. More specifically, we must treat the women we know and love (friends, family, spouses) with that respect and dignity as if Jesus Christ Himself were standing there listening to and watching our conduct.
#YesAllWomen deserve honor, dignity and respect. Let's do our part to give them what they deserve.