Animal rights activists demonstrating in Oxford were handed copies of an injunction barring protests near Oxford University's animal testing centre.
Hundreds of protesters marched through the centre of Oxford in July
Twelve campaigners were served with the papers by Thames Valley Police officers on Saturday in the city centre.
The injunction includes a 45m "no harassment" zone around the South Parks Road centre but allows "restricted" weekly demonstrations.
No arrests were made and the protest was peaceful, a police spokesman said.
Ch Supt Dave McWhirter, of Thames Valley Police, said: "We had a significant number of officers in the city and on standby, and these officers could obviously be better used elsewhere.
"It is unfortunate that the protest organisers did not enter into a dialogue with us so that we could police the demonstration with the appropriate number of officers.
"From our point-of-view it has been a successful operation as we have deterred any criminal activity."