What do "Red Flags" look like?

"My son, if sinners entice you,
Do not consent.

If they say, “Come with us,
Let us lie in wait for blood,
Let us ambush the innocent without cause;

Let us swallow them alive like Sheol,
Even whole, as those who go down to the pit;

We will find all kinds of precious wealth,
We will fill our houses with spoil;

Throw in your lot with us,
We shall all have one purse,”

My son, do not walk in the way with them.
Keep your feet from their path,

For their feet run to evil
And they hasten to shed blood.

Indeed, it is useless to spread the baited net
In the sight of any bird;

But they lie in wait for their own blood;
They ambush their own lives.

So are the ways of everyone who gains by violence;
It takes away the life of its possessors."
Proverbs 1:10-19