Etiquette expert Judith Martin (aka “Miss Manners”) once compared surfing on the Internet to taking a cruise. You’re thrown together with people you’ve never met before and likely will never meet again once the cruise is over. Unfortunately some people take advantage of the relative anonymity such situations offer to behave obnoxiously, to such an extent that they would never dream of doing so in their “real lives” where obnoxious behavior has immediate negative consequences, such as social ostracism.
It may help to keep in mind that those who behave obnoxiously on an Internet site, even a Catholic site, are simply reveling in their anonymity and are not indicative of Catholics in general or the Catholic Church. It might also help to avoid becoming “invested” in any particular argument. Toss your two cents into the hat and leave it at that. Assuming you don’t get sucked into arguing (i.e., you’re able to shrug and say to yourself, “They’re welcome to their opinion”), you can certainly continue reading argument threads for the entertainment value, but should avoid them if you find they are damaging to your spiritual peace.