Contagious Messages


Yankel wished to send an e-mail message to Berel. By
mistake he sent it to Shmerel. Unfortunately, the file attached to the e-mail
was infected with the latest strain of the
Klez virus (so
new that Shmerel’s anti-virus software didn’t spot it). The moment Shmerel
opened the attachment, the screen went blank. When the computer technician
arrived, he had the unpleasant task of informing Shmerel that nearly the
entire contents of his hard disk had been erased by the virus. It took many
hours of hard work—and a lot of money—to restore the computer to its former
state. The technician also managed to identify the source of the offending
e-mail. Shmerel contacted Yankel and asked him to pay the full cost of the
repair. Yankel refused, arguing (a) that he sent the file unintentionally and
(b) that it was Shmerel’s action in opening an unknown file which caused the
virus to enter his computer and destroy its contents. Is there any substance
to Yankel’s arguments?


Reuven places poison in front of Shimon’s cow. The cow
eats and drops dead. Shimon takes Reuven to Beis Din, claiming payment for
his cow. The beraisa
in Tractate Bovo Kamo(47b)
informs us that Beis Din will not uphold his claim. Since it was the cow’s
own action in putting the poison in its mouth which brought about its death,
we can not force Reuven to pay (see
Tosafos ad loco).
He did not cause direct damage, but was only indirectly involved in making
the poison available to the cow (grommo),
which only carries a Heavenly obligation to pay. The law would be the same
even if Reuven were to have mixed the poison into the cow’s feed in a way
which was not discernible to the cow. At the end of the day, the cow’s own
action—and not the person who placed the poison—caused its death (Shach,
Choshen Mishpot

This principle can be applied to our case, argues Rav
Tzvi Spitz (Mishptei
, Bovo
No.67). Yankel is correct in asserting that the damage was
ultimately caused by Shmerel’s own action in opening the infected attachment.
It is true that Yankel sent the virus to Shmerel’s computer, but that
constitutes no more than indirect damage. Had the attachment remained
unopened, it would not have caused any harm. We say to Shmerel that he should
not have opened the file, just as the cow should not have consumed the poison
(without any disrespect to Shmerel!).

However, there are
some viruses which infect the computer automatically, just by viewing the
mail in the preview screen. The moment the user sees the mail in the preview
screen, the virus begins to perform its deadly work. Had this type of virus
been sent by Yankel, albeit unintentionally, he would have been fully liable
for any damage caused to Shmerel’s computer. He actively caused the damage,
without Shmerel’s positive participation. Even if Shmerel only viewed his
mail several days after Yankel sent the message, the law would be the same.

Let us imagine that
Reuven left the front door of his house open and Shimon’s cow walked in,
causing havoc. Could Shimon exempt himself from paying for the damage on the
grounds that Reuven should not have left the door open? Since it is perfectly
normal for people to leave their doors open, we can not fault Reuven for
doing so (see
Bovo Kamo
2:10). On the contrary, it is Shimon who
must ensure that his cow does not cause any harm. Similarly, Rav Spitz would
say looking at one’s mail in a preview window is normal behaviour. When
Yankel sends e-mails, it is
duty to ensure that they are free of
viruses. He can also not exempt himself by arguing that the electronic
impulses he sent have no substance. Whenever damage results from his own
action he is liable, regardless of whether the offending item is of substance
(Steipler Gaon, in
Kehillas Ya’akov
Bovo Kamo,