Therapy, in general, can bring unpleasant thoughts and emotions to the surface.  But processed with the help of your therapist, this experience can lead to greater healing and freedom.  The same risks apply to online counseling.  

For those who are already feeling a great sense of isolation or withdrawal from society, the distance of online counseling may amplify this feeling and in-person therapy may be a more helpful setting.  Additionally, crises or emergency situations are not well-suited for teletherapy, as a therapist is hindered from appropriately intervening.  Moreover, if you are struggling with suicidal thoughts please let your therapist know immediately, as it is highly important to adapt and implement an effective safety plan and assess suitability for teletherapy.