Tim Challies identifies the marks of a false teacher, including this one:
Third, false teachers teach their own wisdom rather than God’s wisdom. False teachers always teach their own foolishness instead of divine wisdom. This means then, that the ultimate source of their teaching is their own minds. It’s their own hearts, it’s their own sinful desires. Listen to what God said through the prophet Jeremiah. He said, “The prophets are prophesying lies in my name. I did not send them, nor did I commend them or speak to them. They are prophesying to you a lying vision, worthless divination, and the deceit of their own minds.” That was true in Jeremiah’s day, it’s just as true in our day.
Imagine what that does for pastors who Tweet (or even elders).