Data In Tables Sometimes Have +

I've noticed as I interact with my database I use for customers, there
are from time to time values that have a strange '+' character. For
example:

forge=# SELECT cust_id, cust_name, cust_contact, cust_email
FROM customers
WHERE cust_name Like 'Truth%';
cust_id | cust_name | cust_contact | cust_email
------------+--------------------+---------------+---------------------
1020105577 | Truth Custom Drums | Geoff Barrios | info(at)truthdrums(dot)com+
| | |
(1 row)

You can see the field called 'cust_email' shows a trailing '+' for
some odd reason. Generally I would chalk this up to fat fingering data
or something but I have seen it on more than a few occasions and
really don't know what it means or why it's there. I know if I use the
'UPDATE' statement and change the address, it goes away:

forge=# UPDATE customers
forge-# SET cust_email = 'info(at)truthdrums(dot)com'
forge-# WHERE cust_id = '1020105577';
UPDATE 1

Now the '+' is obviously gone...

forge=# SELECT cust_id, cust_name, cust_contact, cust_email
FROM customers
WHERE cust_name Like 'Truth%';
cust_id | cust_name | cust_contact | cust_email
------------+--------------------+---------------+---------------------
1000000007 | Truth Custom Drums | Geoff Barrios | info(at)truthdrums(dot)com
(1 row)