I agree with everyone but also would like to add to 'trust your instincts'. There are many people who can and would do anything to satisfy their needs, even get to know you for a long time, even become a best friend of sorts, and then they "pull the rug out from under you". If at any point during or prior to a meeting you get a gut feeling that something is wrong: either be prepared or, the better choice, bail on the meeting (instincts save lives, it works for animals and damn well for us too, just listen to them) My recommendation for something to have/use at all times in this case would be a loud noisemaker, a lighter and your brain. Plan to meet in a place that is teeming with people and during the day, the noisemaker (whistle, horn, etc.) is much more useful and then in W-C-S, use the lighter to burn.
It's all common sense, but it doesn't hurt to be reminded of it from time to time. 🙂