If this is the case in your jurisdiction, than they are going to more trouble than most to prosecute for solicitation.  It is really hard to reach through the internet to bust someone, though it is possible with the right court orders to track ISPs.  I really think this is far fetched, though it might be used in a sting to avoid actually hearing the words said, that a face to face meeting might then be enough, coupled with the ad language.  The standards for an arrest are different from the standards for a conviction...  though if a jury views the ad, it would be hard to convince them you were there for tea.  Keep us posted if any of these cases are adjudicated.
A lot of ads...  CL for instance...  are so flagrant it is hard for LE to ignore.  As long as CL is out there with a bullseye on it's back...  it'll draw the most fire.  
skb