CHICAGO (CBS) — Warnings are being issued about using wireless services within the NATO security zone between downtown and McCormick Place.

As WBBM Newsradio’s Bernie Tafoya reports, cyber security experts say gatherings such as the NATO Summit tend to generate an increase in cyber attacks, whether from self-described anarchists, terrorist groups, anti-war groups, or others.

LISTEN: WBBM Newsradio’s Bernie Tafoya reports

An FBI alert earlier in the month warned that cybercriminals are targeting people who use wireless service in hotels to set up their laptops. A pop-up window will appear asking a user to update some software, but clicking on the window results in the installation of malware, the FBI warned.

Expert Tom Kellermann of the Cupertino, Calif.-based Trend Micro cybersecurity firm tells the Chicago Sun-Times he has also seen an exponential increase in malicious software targeting smart phones and tablets.

Kellermann advises not telling the world your location via FourSquare, Facebook or any other social networking site, and making sure your anti-virus software is up to date, the Sun-Times reports.

Meanwhile, Crain’s Chicago Business reports cell phone companies are beefing up their capacity in the NATO zone.

AT&T, Sprint, U.S. Cellular and Verizon are among the companies that say they are ready for an increase in demand, Crain’s reports.

Experts also tell CBS 2 those in the NATO zone should prepare for accident cutoffs of electricity, and wireless voice and Internet communications.