ATLANTA (AP) -- This college prank is brought to you by the letter `T' and the students at Georgia Tech.

The letter `T' is disappearing from signs all over campus, costing the school more than $100,000 in repairs. Officials at the school in Atlanta are asking students to knock it off.

Undergraduate President Elle Creel tells Fox 5 Atlanta (http://bit.ly/rhIzSg ) the tradition of stealing the `T' off Tech Tower began in the 1960s. But this new ritual involves taking a `T' from everything from stadium signs to book return bins in front of the campus library.

Student Katie Simmons says many buildings have been defaced, and a `T' has already been stolen off a new building.

Student leaders recently launched an amnesty program to try and retrieve some of the letters.