The ornamental design for a protectiveguard for telephones, as shown and described.
FIG. 1 is a perspective view of a protective guard for telephones showing my new design;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a top plan view thereof;
FIG. 4 is a rear elevational thereof;
FIG. 5 is a bottom plan view thereof;
FIG. 6 is a left side elevational view thereof; and,
FIG. 7 is a right side elevational view thereof.
The broken line showing portions of a protective guard for telephone is included for the purpose of illustrating environmental structure and forms no part of the claimed design.