Here’s something you might not have noticed if you were partying it up at SXSW and using Uber to get around: Your Uber might not be permitted in Austin, and the police department wants you to know that.

In a post on the Austin government page, and a subsequent tweet sent out at midnight last night, the local police department has been warning inebriated SXSW attendees to “know the rules of the road” before hiring drivers to take them around town.

SXSW tip: Use only permitted transportation services: http://t.co/3tRY5m6nGx — Austin Police Dept (@Austin_Police) March 8, 2014

When asked if Uber rides were permitted, the police department Twitter replied, “No they are not.”

You should read the whole blog post yourself, but it basically boils down to this:

The Austin Transportation and Police Departments encourage South by Southwest festival goers to use permitted transportation services and to learn the law before registering as drivers for vehicle for hire services during SXSW.

Uber has been offering rides to attendees for the last few years (as well as BBQ), but this year it appears the company has been ramping things up pretty heavily. Previously at SXSW, the company had dispatched pedicabs or unpaid drivers as a way to get around strict Austin for-hire transportation rules.

Those rules include mandating a minimum $55 fare and a 30-minute pre-arrangement period, both of which would make Uber prohibitively expensive and not as convenient. Or, really, useless.

To meet demand this year, Uber shipped in drivers from other cities — at least according to my Uber driver last night, who drove in from Dallas and didn’t know where he was driving any better than I did. The Austin Police Department has a warning for some of those drivers:

In order to drive a ground transportation vehicle, a compensated driver must carry an operating permit, a chauffer’s permit and commercial insurance. Violating any one of these requirements could result in up to a $500 fine, totaling a possible $1,500 fine if all requirements are violated. Additionally, drivers who do not comply with the law risk having their vehicle impounded.

Uber says its UberBLACK drivers follow Austin’s rules since they are licensed and have a minimum fare of $55. It also says there are a “limited number of uberX cars on the system for promotional purposes but they are free,” so they don’t violate the city’s rules.

Someone should tell the folks at the police department before they start fining Uber drivers or scaring attendees away from using the service.