import copy


def truncate_data_strings(data):
    # Deep clone the data to avoid modifying the original object
    cloned_data = copy.deepcopy(data)

    if isinstance(cloned_data, dict):
        for key, value in cloned_data.items():
            # Recursively call the function if the value is a dictionary or a list
            if isinstance(value, (dict, list)):
                cloned_data[key] = truncate_data_strings(value)
            # Truncate the string if it starts with 'data:'
            elif isinstance(value, str) and value.startswith("data:"):
                cloned_data[key] = value[:20]
    elif isinstance(cloned_data, list):
        # Process each item in the list
        cloned_data = [truncate_data_strings(item) for item in cloned_data]

    return cloned_data