What are your biggest online pet peeves (as in message boards, forums, etc.).
For me, the biggest pet peeve is when people use "ECT" as the abbreviation for Et Cetera... ECT is a home pregnancy test, not a latin phrase!

How about you guys?
It can be anything, such as: People posting inane and pointless topics, people who point out others mistakes, people who forget to include an ' in the word "others", ect...