One prominent shul on Pico Blvd emails its members:
In light of the Jewish Institutions security situation in New York, we will be extra cautious this Shabbat. We request your cooperation and compliance with directives. There is no specific threat; we are just being cautious – as advised.
The front doors on Pico will be locked and manned by a security guard.
Please know that you will only be able to enter the Shul from the back gate where we will have an armed guard on duty. This guard works for us on the High Holidays and is familiar with our crowd and routine.
Once you have entered the back gate please be sure to move quickly to where you need to be. Park your strollers in a responsible manner where you will not obstruct exits. Drop your children at their groups and encourage them to remain there. Please advise your children to not engage the guards in conversation or "hang" on Pico. When services are over please try not to linger on Pico in front of the Shul – keep moving along home. Please be alert, and if you observe something "odd" – make note of details and report it to the guards, or if necessary to the police.
Thank you and Shabbat Shalom!