New Delhi, Jan 8 (ANI): After the Aam Aadmi Party's office in Kaushambi was attacked by a group of 30 to 40 activists, claiming to be from the Hindu Rakshak Sena, AAP leader Prashant Bhushan expressed disappointment over the matter. Bhushan said that the protestors are linked to the BJP, and this act highlights the frustration of the party.