Last Friday there was a big raid in the zona by the Mexican FEDs! I believe this is the biggest one to date, as there has been others where the TJ police go inside the bars and detain everybody, check IDs and do a weapons search, and I guess check for drugs, and if you have something like a weapon or drugs they arrest you.
I don't even know the exact reason for the raid? I think one article said it was a immigration check, but who knows?
It also looks like some of those cops were up to their old tricks because a lot of bar girls reported being robbed by these rogue cops up in their hotel rooms, and a few locals, and perhaps a few mongers reported being robbed too.
I wouldn't worry too much about these raids, but they do happen from time to time. And I have a feeling they won't happened for months now, because this last raid pissed a lot of people off, especially with allegations about the cops robbing people in the zona.
Just be sure you don't have weapons, drugs, or too much money in you wallet, and chances are if a raid ever does take place, you will only be searched and asked for an ID.
Here are some pictures of the zona raid last Friday: ( so far I been lucky, as I never been in TJ during these bars raids)
http://www.frontera.info/galerias/homeNew.aspx?numgaleria=13391