The purest form of tyrrany is rape. The purest form of democracy is gang-rape.
Anarchist opposition to democracy stems not from the agreement among peoples to implement solutions to common viewed problems, but on the use of force to make others help provide such solutions, or attempts at solutions, against their will. Since modern democracy implies power of the majority to command the minority, it is an immoral system; in the same way that a single tyrant is immoral in forcing his will on someone else.