I saw a couple of responses of people recommending a certain agency and visiting hotels.
First, almost all of us in the hobby know that no matter what the house mother who runs the agency says, they do keep records. They all do, even if it's coded, LE can usually crack it eventually and this provides your phone number and whatever name you are using. (Be smart, use a hobby name and a hobby phone. Never use one that ties to your home or business.)
Second, you always, always, ALWAYS run the risk that an agency has been compromised, especiallyif you're visiting the girl at her hotel. You always take a gamble that yes, that may be her on the phone when you speak, but you have no idea if she's already been arrested and being coerced into cooperating with a sting to arrest hobbyists.
Finally, never, never, never go to the hotel a provider is using. While you may have been lucky so far, it only takes one time for you to be wrong for you to be arrested. It doesn't matter if you work your way out of it, your name may get published in places that eventually reveal your situation to friends and family.
Always take precautions to not only be safe in your hobbying antics, but to be safe in where you go and who you see. This is not meant to insult any of the lovely women who work with agencies, but how many times have you read about an agency being compromised, names being made available, etc. My point is, you don't know until it's too late.