Hermosa E-bikes

What’s the point of the giant electronic sign on the Hermosa Pier stating the use of e-bikes on the strand is prohibited along with the metal signs on the strand stating e-bikes must be used under manual power if the HBPD do nothing to enforce it? I Witnessed multiple groups of masked teens/preteens on non pedal motorcycle style e-bikes doing at least 30mph over the past week on and around the strand including a group of teens who love to ride down the street yelling the N word at people.